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Design and analysis of composite belt for high rise elevators
Materials Today: Proceedings xxx (xxxx) xxx
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Design and analysis of composite belt for high rise elevators R. Sujith Kumar a, G. Swaminathan a, Ganesh Babu Loganathan b a b
Department of Mechanical Engineering, SRM Institute of Science and Technology, Ramapuram, Chennai, India Department of Mechatronics Engineering, Tishk International University, Erbil, KRG, Iraq
a r t i c l e
i n f o
Article history: Received 10 June 2019 Received in revised form 17 September 2019 Accepted 20 September 2019 Available online xxxx Keywords: Composite Unidirectional Bi-directional Glass fiber Carbon fiber
a b s t r a c t This paper describes and evaluates the mechanical properties of glass and carbon fiber composites for high-rise applications by theoretically comparing and experimentally replacing conventional steel cables. The tensile and bending strength to weight ration of these fibers are extremely high such that the selfweight of the hoisting mechanism is reduced to a larger quantity, which enables to travel twice that of the present travel limitations. Both Unidirectional and bidirectional glass and carbon fibers have been analyzed with different combinations to compare mechanical properties. Significant increases in mechanical properties were absorbed in both fiber combinations. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
1. Introduction A composite material is a combination of two materials which combinedly gives the property superior to that of the other individual constituents. The ultimate reason for choosing composite materials is because of their weight saving for its relative stiffness and strength. In this work, epoxy is commonly used a matrix with some additives in the experiments (See Table 1). As the construction of high-rise buildings are getting higher, their logistical demands are also with them. A revolutionary breakthrough is required in vertical transportation, when the existing technology and solutions can be taken no further to meet the urban environments of the future. Elevator uses conventional steel ropes for hoisting purposes which is limited to a travel of maximum 500 m and the energy consumption is very high for high rise buildings. To make the elevator travel >500 m, the self-weight of the components needs to be reduced and the main drawback of conventional steel ropes is its weight (See Table 2). So, the concept of the modern rope (Fig. 2) is a new method of hoisting that reduces the demerits of conventional steel rope by using composite materials. This type of new rope is set to crack the industry limits and enable to make the travel heights of 1000 m (3280 ft), twice the distance that is currently feasible. Reduction in self-weight of steel ropes leads to
Travel elevator >500 m less weight in compensation ropes less energy consumption by the machine Throughout the research and development phase, there is a clear need for exploration and interpretation of the technical literature. The first step in the investigation is to make a thorough review of the corresponding work before. The review process includes specific information, a detailed survey and a preliminary review. This article also reviewed a series of peer-reviewed journal articles to illustrate the properties of the composites. 2. Experimental details 2.1. Design calculations 2.1.1. Selection of fiber, resin and volume fraction Among the natural and artificial fibers, glass and carbon fibers were consolidated for further studies considering its thermomechanical properties based on the literatures. Epoxy resin seems to be more superior in thermo-mechanical properties and in environments amidst polyester, epoxy, vinyl ester, phenolic and polyurethane. Fiber volume fraction has been calculated by the below formulae,
https://doi.org/10.1016/j.matpr.2019.09.063 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
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Table 1 Literature review. Composite materials has been used for several applications in the industry but were limited for only certain applications. By using composite in the elevator industry, it may extend its operation beyond its present situations. In the current scenario, an elevator can only travel up to a range of 300 m, due to adding self-weight of the rope for higher travel. So composite material can be implemented to reduce the self-weight of the rope and enabling to travel >300 m. Ref. No.
Authors
Year
Objective and Outcomes
[1]
N. Ozsoy*, A. Mimaro§lu
2014
[2]
T D Jagannatha and G Harish
2015
[3]
Ever J. Barbero
2004
[4]
Pop P. Adrian1, Bejinaru Mihoc Gheorghe N. I. Baurova, Wei Hao, Ouyang Xiao
2010
G. Agarwal, A. Patnaik,, R. K. Sharma Rick Perry, Martin Rhiner and Kevin Heling S. Eksi and K. Genel
2014 2008
Behavior of the composite were studied and seems that the 0 degree CFRE has performed better in all the aspects of the test that has been carried out The polymer composite reinforced with a carbon fiber mat dramatically improved the tensile strength, the yield strength and the maximum load of the composite Provides a complete step by step, predictive analysis of the stiffness properties of the pultruded structural shapes. It is also useful for estimation of structural properties of a large variety of structural shapes. Presented some of the fabrication techniques of composite materials based on its type, application, quality parts, size of production etc., It states that the carbon fiber of the UKN-2500 brand has a large number of initial failures in the form of contamination along its entire length, resulting in a fragile and adhesive destruction of the composite material reinforced with carbon fiber Fiber loading has been varied to study the mechanical properties of bi-directional and short carbon fiber reinforced epoxy composites To understand the traction hoist ropes in elevators and the factors that adversely affect the rope life
2017
Mechanical behavior of epoxy composite reinforced unidirectional and woven fiber is investigated experimentally.
[5]
[6] [7] [8]
2013
Table 2 Specifications of the fabrics, epoxy and hardener.
FVF ¼
½1 þ qqmf
Description
Values
Layer 0 (E-glass) Layer 90 (E-glass) Area weight 0 Area weight 90 Layer 0 (carbon) Density (Epoxy) Viscosity (Epoxy) Density (Hardener) Viscosity (Hardener)
240 gsm 200 gsm 0.142 g/m2 0.236 g/m2 0.180 g/m2 1200 kg/m3 0.9 N-s/m2 950 kg/m3 0.1 N-s/m2
1 1 FWF
1
where FVF ¼ FiberVolumeFraction FWF = Fiber Weight Fraction qf = Density of Fiber qm = Density of Matrix 2.1.2. Selection of the optimum fiber orientation and lamina stacking sequence Both Bi-directional woven carbon and glass fiber mats & Undirectional fiber mats with 0° and 90° orientation angles are used to study its mechanical properties Symmetrical lamina stacking sequence has been adapted to obtain better properties as discussed in the literatures The ultimate objective is to use composite material instead of steel ropes in elevators. So, the composite material should withstand the forces that acts towards it. 2.1.3. Rope force calculation Fig. 1 represents the schematic of an elevator operation. From the figure, force acting on the suspension rope is a product of the acceleration due to gravity and the car movement with respect to the subjected load on the ropes. Thus, the equation can be written as,
Rope force ¼ ½ðg þ aÞðQ þ Mcar þ MCRcar þ MTCÞ
Fig. 1. Rope force calculation.
where g = acceleration due to gravity (m/s2) a = acceleration of the moving car (m/s2) Q = Rated load (kg) Mcar = Mass of the total cabin (kg) MCRcar = Mass of the compensation rope in car (kg) MTC = Mass of the travelling cable (kg) To approximate these rope calculations, the following conditions were assumed for Travel of the elevator = 800 m Speed = 15 m/s Rated load = 1000 kg Mass of the compensation rope = 1.5 kg/m Mass of the Traveling cable = 1.5 kg/m
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
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Fig. 4. Hand Lay-up process. Fig. 2. Proposed composite belt.
2.2. Materials
By calculations, all up load of the cabin with frame, Mcar = 885 kg So the total forces that are acting in ropes is 50.65 KN. The composite belt that we are developing should withstand a minimum strength of 50.65 KN to overcome the forces that are developed during the vertical travel of an elevator. The above calculation is to design the composite belt to overcome the overall lifting force. But a pressure will be created over the rope surface during tension and due to the load factor of the elevator. So, to calculate the surface pressure,
2.1.4. Surface pressure of rope, p ¼
" Surface pressure of rope; p ¼
8 cos ðb2Þ = 7.75 m/mm2 x pbsinb
T ndD
T x ndD
8 cos
b !# 2
p bsinb
where p = surface pressure (N/mm2) T = static force in ropes on car side near traction sheave when car is at bottom landing with rated load (N) = 50.65 kN n = number of suspension ropes = 8 Nos. d = width of a rope (mm) = 10 mm D = diameter of the traction sheave (mm) = 520 mm b = undercut angle (rad) = 100° = 1.745 rad Surface pressure of rope not only depends on the static force in ropes and its size, number and the sheave diameter but mainly depends on the undercut angle in which the rope passes over the pulley without any slippage.
3(a)
3(b)
The below diagram Fig. 3 represents fiber and matrix arrangement that to be manufactured as composite belt for elevator applications. Since the composite belt for this high rise elevator applications should be lengthy in 1000 s of meters, this can be manufactured only through pultrusion process. But for understanding the mechanical behavior of these composites, hand lay-up method were used for fabrication with various combinations. Unidirectional and bidirectional glass fiber fabric as well as carbon fiber were used as reinforcing material and epoxy is used as matrix. Epoxy resin (MGS L285) were mixed with hardener (HGS L285) in a proportionate mass ration of 100/40 as recommended by the supplier. The composites were cured at a room temperature for 24 h. To suit the test facility, the materials were cut in to the sizes as mentioned in Table 3 and in Fig. 5 for examining the mechanical properties (See Figs. 6 and 7).
2.3. Methods Hand Lay-up method of composite fabrication is used for all the variants of fiber and matrices as shown in Fig. 4. Hand Lay-up is a molding process where fiber reinforcements are placed by hand then with wet resin. The manual nature of this process allows for almost any reinforcing material to be considered, chopped strand or mat. Similarly, the resin and catalyst blend can be manipulated to allow for ideal processing solutions (See Figs. 8 and 9). 8plies of Uni-directional fibers has been stacked symmetrically to attain the required thickness of the composite as represented in the Fig. 5. 4plies of Bi-directional fibers has been stacked symmetrically to attain the required thickness of the composite (See Figs. 10 and 11). Table 3 Dimensions of test specimen. Property
Length (mm)
Width (mm)
Thickness (mm)
Tensile Flexural Impact
150 150 150
25.4 25.4 25.4
3 3 3
3(c)
3(d)
Fig. 3. (a) Woven glass fiber, (b) Woven carbon fiber, (c) Unidirectional carbon fiber, (d) Unidirectional glass fiber.
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
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Fig. 7. Ply stacking- Bidirectional fibers.
5 (a)
5(b)
5(c)
5(d)
Fig. 5. Unidirectional Glass and Carbon, Bidirectional Glass and Carbon fibers respectively.
Fig. 6. Ply stacking –Unidirectional fibers.
2.4. Testing A Universal Testing Machine (UTM) is used for carrying out the tensile and the bending test for the specimen prepared and the Izod Testing machine for carrying out the impact testing (See Figs. 12 and 13). During the tensile tests breaking has occurred in the middle of the composites and the material deformation and their respective tensile strength has been recorded in the Table 4. For flexural, three point bending test has been carried out and it has stopped automatically when the plastic deformation started in the composite. Each test were repeated on five samples and the average value were considered and tabulated below (See Figs. 14 and 15).
2.5. Analytical testing Examining the tensile and the flexural strength of these glass and carbon fiber composites analytically through ANSYS 18.1.
Fig. 8. Universal testing machine.
The following conditions were considered to analyze the mechanical behavior of these composites. 1. A model of 25.4 150 mm were considered same as like experimental model. 2. All DOF is constrained.
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
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Fig. 11. Boundary condition for tensile test.
Fig. 9. Impact testing.
UX & UY CONSTRAINED
Fig. 12. Boundary condition for Tensile test.
Fig. 10. Tensile test.
3. For 0° and 0°/90° orientation, 8 number of plies were considered as like experimental model. 4. For Bidirectional fibers, 4 numbers of plies were considered as like experimental model based on the density and thickness. 2.5.1. Boundary condition a. For tensile test, UY and UZ has been constrained since the elongation will be parallel to the direction of load applied.
Fig. 13. Load condition for flexural test.
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
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Table 4 Experimental results. Reinforcement type
Tensile strength (MPa)
Flexural load (kN)
Impact values (J)
Unidirectional. glass (0°) Unidirectional glass (0°/90°) Bidirectional glass Unidirectional. carbon (0°) Unidirectional. carbon (0°/90°) Bidirectional carbon
167.85 111.35 173.97 608.24 472.19 333.47
0.81 0.54 0.27 1.47 0.96 0.46
2 2 2 2 2 2
Fig. 16. Flexural strength in 0° unidirectional glass fiber.
Fig. 14. Tensile strength in 0° UD glass fiber.
Fig. 17. Tensile strength in 0°/90° UD glass fiber.
Fig. 15. Structural deformation.
b. For flexural, UX and UY has been constrained since the load is being applied vertically and the specimen tends to vary or bend in the z-direction i.e., the direction of load. 2.5.2. Case (i): 0° unidirectional glass fiber Tensile strength refers to the amount of stress a material can handle before it breaks, cracks, becomes deformed or otherwise fails. From the result, we could see that the max tensile strength obtained is 166.102 N and the material is deformed by 1.64 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. Flexural test is by applying a defined load in the middle of the specimen to check the bending ability of the model before its
Fig. 18. Structural deformation.
breaking point. From the Fig. 16, we could see that the material tends to bend due to the applied load and it could resist from breaking with a load of 9.245 kN (See Fig. 17).
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Fig. 19. Flexural strength in 0°/90° unidirectional glass fiber.
Fig. 20. Tensile strength in Bidirectional glass fiber.
7
Fig. 22. Flexural strength in Bidirectional glass fiber.
Fig. 23. Tensile strength in 0° UD carbon fiber.
Fig. 21. Structural deformation. Fig. 24. Structural deformation.
2.5.3. Case (ii): 0°/90° unidirectional glass fiber From the above result, we could see that the max tensile strength obtained is 110.335 N and the material is deformed by 0.201 mm. Since the material is clamped at both the ends the
higher stress can be visualized in the middle region shown by red color (See Fig. 18).
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
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Fig. 25. Flexural strength in 0° unidirectional glass fiber.
Fig. 28. Flexural strength in 0°/90° unidirectional glass fiber.
Fig. 26. Tensile strength in 0°/90° UD carbon fiber.
Fig. 29. Tensile strength in Bidirectional carbon fiber.
Fig. 27. Structural deformation.
Fig. 30. Structural deformation.
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Flexural strength identifies the amount of strength and force a structure can withstand such that it resists any bending failures. In this unidirectional fiber, both the ends are clamped to test its bending ability, the structure is varying non-linearly as in the Fig. 19. A non-linear structure will not be suitable for a higher travel applications and the breaking point is found at 7.06 kN (See Fig. 20 and 21). 2.5.4. Case (iii): Bidirectional glass fiber From the above plot, we could see that the bidirectional glass fiber offers better tensile strength than the unidirectional fiber.
9
Area where the stress acts can be seen in red color and it is not distributed throughout its area like the unidirectional fibers. Maximum tensile strength obtained is 171.297 N and the material is deformed by 0.863 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. As seen in the 0°/90° unidirectional glass fiber, the specimen is varying non-linearly on applying load. From the Fig. 22, we could see that the material tends to bend due to the applied load but the force distribution is not even throughout its structure. Since this composite belt should roll over a machine sheave, this should be good in its flexural ability. 2.5.5. Case (iv): 0° unidirectional carbon fiber From the above result, we could see that the max tensile strength obtained is 594.711 N and the material is deformed by 5.606 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. Among all the fibers we have discussed, unidirectional carbon fiber seems to offer better tensile strength and the material tends to deform instead of breaking down (See Figs. 23 and 24). Amidst all the glass fibers, the 0° unidirectional carbon fiber is varying its structure uniformly on applying the load and the maximum strength is visualized at 12.65 kN. From the Fig. 25, we could see that the center region undergoes high bending with linear variation in the structure (See Figs. 26 and 27). 2.5.6. Case (v): 0°/90° unidirectional carbon fiber From the above result, we could see that the max tensile strength obtained is 448.296 N and the material is deformed by
Fig. 31. Flexural strength in Bidirectional carbon fiber.
Fig. 32. Tensile strength chart.
Fig. 33. Flexural strength chart.
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Table 5 Data’s obtained through analysis. Reinforcement type
Tensile strength (MPa)
Deformation-tensile (mm)
Applied load (kN)
Flexural load (kN)
Unidirectional. glass (0°) Unidirectional glass (0°/90°) Bidirectional glass Unidirectional. carbon (0°) Unidirectional. carbon (0°/90°) Bidirectional carbon
166.102 110.335 171.297 594.711 448.296 332.525
1.64 0.2017 0.863 5.60 0.703 1.741
13.47 10.010 14.20 40.0 21.70 28.43
9.245 7.065 3.600 12.6541 9.643 5.892
0.703 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. The strength required to break the material is little lesser as compared to the zero degree unidirectional carbon fiber. Carbon fibers seems to offer good flexural strength as compared to the glass fibers, but the 0° unidirectional carbon fibers offer better results than 0°/90° unidirectional carbon fiber and can be seen in the Fig. 28. 2.5.7. Case (vi): Bidirectional carbon fiber From the above result, we could see that the max tensile strength obtained is 332.525 N and the material is deformed by 1.74106 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color (See Figs. 29 and 30). Bidirectional carbon fibers offers a linear variation of the structure along the direction of load applied. And the maximum stress can be seen in red in color in the Fig. 31. But it can withstand only a load of 5.892 kN whereas unidirectional carbon and 0° degree unidirectional glass fiber has better bending strength comparatively (See Figs. 32 and 33). 3. Results and discussion Tensile strength and the flexural strength of the Glass fiber reinforced composites and the Carbon Fiber Reinforced Composites are shown in Tables 4 and 5. From the results, carbon fiber epoxy reinforced composites has the high strain compared to the glass fiber reinforced composites. The tensile strength of the glass fibers were almost similar and their strain ratio changes accordingly. But the carbon fiber epoxy reinforced composites has possess the highest tensile strength in all its orientation. And the 0° unidirectional carbon fiber has the highest tensile strength with higher strain ratio as compared to the other composites. The tensile strength and flexural strength of glass and carbon fiber epoxy reinforced composite is shown in the chart below. In this case, composite with 0° orientation has the higher flexural strength similar to the tension results. According to the test results, 0°/90° unidirectional and bidirectional glass fiber had the lowest tensile and flexural strength. When the composites were compared according to the tensile and the flexural strength, carbon fiber reinforced composites had better performances, because car-
bon fiber as a single filament has better mechanical properties compared to the glass fibers. 4. Conclusion In this study, mechanical properties of bi-directional and unidirectional fiber reinforced epoxy composites were investigated. To employ the fiber re-inforced composite in elevators, the composite should withstand the rope forces that has been calculated previously. Linear variation in bending of structure is required to make the composite roll around a motor sheave for traction and the proposed design of composite should be high in tensile strength since this will undergo tension during loading of passengers and goods. Unidirectional carbon fibers has the more tensile and flexural strength [N. Ozsoy*, A. Mimaro§lu, M.I. Ozsoy, 2014]. All the fibers, such as bidirectional and unidirectional glass and carbon fibers will withstand the forces since their tensile strength are greater than 50.62 KN. But comparatively, the 0° unidirectional reinforced carbon fiber composite has the high tensile strength and their flexural strength are way better amidst the other fibers and their orientations, which has the most priority in the selection of ropes in elevator. So from the above data’s, the best result of tensile and bending strength is found in 0° orientation of unidirectional carbon fiber reinforced epoxy composite comparatively with the other tested composite materials and can be employed in high rise elevator applications. References [1] N. Ozsoy*, A. Mimaro§lu, M.I. Ozsoy, 2014 ‘Comparison of Mechanical Behaviour of Carbon and Glass Fiber Reinforced Epoxy Composites’, 4th International Congress APMAS2014. [2] POP P. Adrian1, BEJINARU MIHOC Gheorghe2, 2010 ‘Manufacturing Process and Applications of Composite Materials’, Fascicle of Management and Technological Engineering, Volume IX (XIX), NR2. [3] Ettore Coggi, Milan, Italy, 1961 ‘Composite Ropes, Cords and the Like’ 13 claims (Cl. 87-1) [4] T.D. Jagannatha, G. Harish, Mechanical properties of carbon/glass fiber reinforced epoxy hybrid polymer composites, Int. J. Mech. Eng. Rob. Res. 4 (2) (2015). [5] F.C. Campbell, Manufacturing Processes for Advanced Composites, Elsevier Advanced Technology, 2004. [6] P.K. Mallick, Fiber Re-Inforced Composites, Third Ed. CRC Press. [7] J.M.L. Reis, J.L.V. Coelho, A.H. Monteiro, H.S. Da Costa Mattos, Compos. B 43 (2012) 2041.
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Design and analysis of composite belt for high rise elevators R. Sujith Kumar a, G. Swaminathan a, Ganesh Babu Loganathan b a b
Department of Mechanical Engineering, SRM Institute of Science and Technology, Ramapuram, Chennai, India Department of Mechatronics Engineering, Tishk International University, Erbil, KRG, Iraq
a r t i c l e
i n f o
Article history: Received 10 June 2019 Received in revised form 17 September 2019 Accepted 20 September 2019 Available online xxxx Keywords: Composite Unidirectional Bi-directional Glass fiber Carbon fiber
a b s t r a c t This paper describes and evaluates the mechanical properties of glass and carbon fiber composites for high-rise applications by theoretically comparing and experimentally replacing conventional steel cables. The tensile and bending strength to weight ration of these fibers are extremely high such that the selfweight of the hoisting mechanism is reduced to a larger quantity, which enables to travel twice that of the present travel limitations. Both Unidirectional and bidirectional glass and carbon fibers have been analyzed with different combinations to compare mechanical properties. Significant increases in mechanical properties were absorbed in both fiber combinations. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
1. Introduction A composite material is a combination of two materials which combinedly gives the property superior to that of the other individual constituents. The ultimate reason for choosing composite materials is because of their weight saving for its relative stiffness and strength. In this work, epoxy is commonly used a matrix with some additives in the experiments (See Table 1). As the construction of high-rise buildings are getting higher, their logistical demands are also with them. A revolutionary breakthrough is required in vertical transportation, when the existing technology and solutions can be taken no further to meet the urban environments of the future. Elevator uses conventional steel ropes for hoisting purposes which is limited to a travel of maximum 500 m and the energy consumption is very high for high rise buildings. To make the elevator travel >500 m, the self-weight of the components needs to be reduced and the main drawback of conventional steel ropes is its weight (See Table 2). So, the concept of the modern rope (Fig. 2) is a new method of hoisting that reduces the demerits of conventional steel rope by using composite materials. This type of new rope is set to crack the industry limits and enable to make the travel heights of 1000 m (3280 ft), twice the distance that is currently feasible. Reduction in self-weight of steel ropes leads to
Travel elevator >500 m less weight in compensation ropes less energy consumption by the machine Throughout the research and development phase, there is a clear need for exploration and interpretation of the technical literature. The first step in the investigation is to make a thorough review of the corresponding work before. The review process includes specific information, a detailed survey and a preliminary review. This article also reviewed a series of peer-reviewed journal articles to illustrate the properties of the composites. 2. Experimental details 2.1. Design calculations 2.1.1. Selection of fiber, resin and volume fraction Among the natural and artificial fibers, glass and carbon fibers were consolidated for further studies considering its thermomechanical properties based on the literatures. Epoxy resin seems to be more superior in thermo-mechanical properties and in environments amidst polyester, epoxy, vinyl ester, phenolic and polyurethane. Fiber volume fraction has been calculated by the below formulae,
https://doi.org/10.1016/j.matpr.2019.09.063 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063
2
R. Sujith Kumar et al. / Materials Today: Proceedings xxx (xxxx) xxx
Table 1 Literature review. Composite materials has been used for several applications in the industry but were limited for only certain applications. By using composite in the elevator industry, it may extend its operation beyond its present situations. In the current scenario, an elevator can only travel up to a range of 300 m, due to adding self-weight of the rope for higher travel. So composite material can be implemented to reduce the self-weight of the rope and enabling to travel >300 m. Ref. No.
Authors
Year
Objective and Outcomes
[1]
N. Ozsoy*, A. Mimaro§lu
2014
[2]
T D Jagannatha and G Harish
2015
[3]
Ever J. Barbero
2004
[4]
Pop P. Adrian1, Bejinaru Mihoc Gheorghe N. I. Baurova, Wei Hao, Ouyang Xiao
2010
G. Agarwal, A. Patnaik,, R. K. Sharma Rick Perry, Martin Rhiner and Kevin Heling S. Eksi and K. Genel
2014 2008
Behavior of the composite were studied and seems that the 0 degree CFRE has performed better in all the aspects of the test that has been carried out The polymer composite reinforced with a carbon fiber mat dramatically improved the tensile strength, the yield strength and the maximum load of the composite Provides a complete step by step, predictive analysis of the stiffness properties of the pultruded structural shapes. It is also useful for estimation of structural properties of a large variety of structural shapes. Presented some of the fabrication techniques of composite materials based on its type, application, quality parts, size of production etc., It states that the carbon fiber of the UKN-2500 brand has a large number of initial failures in the form of contamination along its entire length, resulting in a fragile and adhesive destruction of the composite material reinforced with carbon fiber Fiber loading has been varied to study the mechanical properties of bi-directional and short carbon fiber reinforced epoxy composites To understand the traction hoist ropes in elevators and the factors that adversely affect the rope life
2017
Mechanical behavior of epoxy composite reinforced unidirectional and woven fiber is investigated experimentally.
[5]
[6] [7] [8]
2013
Table 2 Specifications of the fabrics, epoxy and hardener.
FVF ¼
½1 þ qqmf
Description
Values
Layer 0 (E-glass) Layer 90 (E-glass) Area weight 0 Area weight 90 Layer 0 (carbon) Density (Epoxy) Viscosity (Epoxy) Density (Hardener) Viscosity (Hardener)
240 gsm 200 gsm 0.142 g/m2 0.236 g/m2 0.180 g/m2 1200 kg/m3 0.9 N-s/m2 950 kg/m3 0.1 N-s/m2
1 1 FWF
1
where FVF ¼ FiberVolumeFraction FWF = Fiber Weight Fraction qf = Density of Fiber qm = Density of Matrix 2.1.2. Selection of the optimum fiber orientation and lamina stacking sequence Both Bi-directional woven carbon and glass fiber mats & Undirectional fiber mats with 0° and 90° orientation angles are used to study its mechanical properties Symmetrical lamina stacking sequence has been adapted to obtain better properties as discussed in the literatures The ultimate objective is to use composite material instead of steel ropes in elevators. So, the composite material should withstand the forces that acts towards it. 2.1.3. Rope force calculation Fig. 1 represents the schematic of an elevator operation. From the figure, force acting on the suspension rope is a product of the acceleration due to gravity and the car movement with respect to the subjected load on the ropes. Thus, the equation can be written as,
Rope force ¼ ½ðg þ aÞðQ þ Mcar þ MCRcar þ MTCÞ
Fig. 1. Rope force calculation.
where g = acceleration due to gravity (m/s2) a = acceleration of the moving car (m/s2) Q = Rated load (kg) Mcar = Mass of the total cabin (kg) MCRcar = Mass of the compensation rope in car (kg) MTC = Mass of the travelling cable (kg) To approximate these rope calculations, the following conditions were assumed for Travel of the elevator = 800 m Speed = 15 m/s Rated load = 1000 kg Mass of the compensation rope = 1.5 kg/m Mass of the Traveling cable = 1.5 kg/m
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Fig. 4. Hand Lay-up process. Fig. 2. Proposed composite belt.
2.2. Materials
By calculations, all up load of the cabin with frame, Mcar = 885 kg So the total forces that are acting in ropes is 50.65 KN. The composite belt that we are developing should withstand a minimum strength of 50.65 KN to overcome the forces that are developed during the vertical travel of an elevator. The above calculation is to design the composite belt to overcome the overall lifting force. But a pressure will be created over the rope surface during tension and due to the load factor of the elevator. So, to calculate the surface pressure,
2.1.4. Surface pressure of rope, p ¼
" Surface pressure of rope; p ¼
8 cos ðb2Þ = 7.75 m/mm2 x pbsinb
T ndD
T x ndD
8 cos
b !# 2
p bsinb
where p = surface pressure (N/mm2) T = static force in ropes on car side near traction sheave when car is at bottom landing with rated load (N) = 50.65 kN n = number of suspension ropes = 8 Nos. d = width of a rope (mm) = 10 mm D = diameter of the traction sheave (mm) = 520 mm b = undercut angle (rad) = 100° = 1.745 rad Surface pressure of rope not only depends on the static force in ropes and its size, number and the sheave diameter but mainly depends on the undercut angle in which the rope passes over the pulley without any slippage.
3(a)
3(b)
The below diagram Fig. 3 represents fiber and matrix arrangement that to be manufactured as composite belt for elevator applications. Since the composite belt for this high rise elevator applications should be lengthy in 1000 s of meters, this can be manufactured only through pultrusion process. But for understanding the mechanical behavior of these composites, hand lay-up method were used for fabrication with various combinations. Unidirectional and bidirectional glass fiber fabric as well as carbon fiber were used as reinforcing material and epoxy is used as matrix. Epoxy resin (MGS L285) were mixed with hardener (HGS L285) in a proportionate mass ration of 100/40 as recommended by the supplier. The composites were cured at a room temperature for 24 h. To suit the test facility, the materials were cut in to the sizes as mentioned in Table 3 and in Fig. 5 for examining the mechanical properties (See Figs. 6 and 7).
2.3. Methods Hand Lay-up method of composite fabrication is used for all the variants of fiber and matrices as shown in Fig. 4. Hand Lay-up is a molding process where fiber reinforcements are placed by hand then with wet resin. The manual nature of this process allows for almost any reinforcing material to be considered, chopped strand or mat. Similarly, the resin and catalyst blend can be manipulated to allow for ideal processing solutions (See Figs. 8 and 9). 8plies of Uni-directional fibers has been stacked symmetrically to attain the required thickness of the composite as represented in the Fig. 5. 4plies of Bi-directional fibers has been stacked symmetrically to attain the required thickness of the composite (See Figs. 10 and 11). Table 3 Dimensions of test specimen. Property
Length (mm)
Width (mm)
Thickness (mm)
Tensile Flexural Impact
150 150 150
25.4 25.4 25.4
3 3 3
3(c)
3(d)
Fig. 3. (a) Woven glass fiber, (b) Woven carbon fiber, (c) Unidirectional carbon fiber, (d) Unidirectional glass fiber.
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Fig. 7. Ply stacking- Bidirectional fibers.
5 (a)
5(b)
5(c)
5(d)
Fig. 5. Unidirectional Glass and Carbon, Bidirectional Glass and Carbon fibers respectively.
Fig. 6. Ply stacking –Unidirectional fibers.
2.4. Testing A Universal Testing Machine (UTM) is used for carrying out the tensile and the bending test for the specimen prepared and the Izod Testing machine for carrying out the impact testing (See Figs. 12 and 13). During the tensile tests breaking has occurred in the middle of the composites and the material deformation and their respective tensile strength has been recorded in the Table 4. For flexural, three point bending test has been carried out and it has stopped automatically when the plastic deformation started in the composite. Each test were repeated on five samples and the average value were considered and tabulated below (See Figs. 14 and 15).
2.5. Analytical testing Examining the tensile and the flexural strength of these glass and carbon fiber composites analytically through ANSYS 18.1.
Fig. 8. Universal testing machine.
The following conditions were considered to analyze the mechanical behavior of these composites. 1. A model of 25.4 150 mm were considered same as like experimental model. 2. All DOF is constrained.
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Fig. 11. Boundary condition for tensile test.
Fig. 9. Impact testing.
UX & UY CONSTRAINED
Fig. 12. Boundary condition for Tensile test.
Fig. 10. Tensile test.
3. For 0° and 0°/90° orientation, 8 number of plies were considered as like experimental model. 4. For Bidirectional fibers, 4 numbers of plies were considered as like experimental model based on the density and thickness. 2.5.1. Boundary condition a. For tensile test, UY and UZ has been constrained since the elongation will be parallel to the direction of load applied.
Fig. 13. Load condition for flexural test.
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Table 4 Experimental results. Reinforcement type
Tensile strength (MPa)
Flexural load (kN)
Impact values (J)
Unidirectional. glass (0°) Unidirectional glass (0°/90°) Bidirectional glass Unidirectional. carbon (0°) Unidirectional. carbon (0°/90°) Bidirectional carbon
167.85 111.35 173.97 608.24 472.19 333.47
0.81 0.54 0.27 1.47 0.96 0.46
2 2 2 2 2 2
Fig. 16. Flexural strength in 0° unidirectional glass fiber.
Fig. 14. Tensile strength in 0° UD glass fiber.
Fig. 17. Tensile strength in 0°/90° UD glass fiber.
Fig. 15. Structural deformation.
b. For flexural, UX and UY has been constrained since the load is being applied vertically and the specimen tends to vary or bend in the z-direction i.e., the direction of load. 2.5.2. Case (i): 0° unidirectional glass fiber Tensile strength refers to the amount of stress a material can handle before it breaks, cracks, becomes deformed or otherwise fails. From the result, we could see that the max tensile strength obtained is 166.102 N and the material is deformed by 1.64 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. Flexural test is by applying a defined load in the middle of the specimen to check the bending ability of the model before its
Fig. 18. Structural deformation.
breaking point. From the Fig. 16, we could see that the material tends to bend due to the applied load and it could resist from breaking with a load of 9.245 kN (See Fig. 17).
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Fig. 19. Flexural strength in 0°/90° unidirectional glass fiber.
Fig. 20. Tensile strength in Bidirectional glass fiber.
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Fig. 22. Flexural strength in Bidirectional glass fiber.
Fig. 23. Tensile strength in 0° UD carbon fiber.
Fig. 21. Structural deformation. Fig. 24. Structural deformation.
2.5.3. Case (ii): 0°/90° unidirectional glass fiber From the above result, we could see that the max tensile strength obtained is 110.335 N and the material is deformed by 0.201 mm. Since the material is clamped at both the ends the
higher stress can be visualized in the middle region shown by red color (See Fig. 18).
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Fig. 25. Flexural strength in 0° unidirectional glass fiber.
Fig. 28. Flexural strength in 0°/90° unidirectional glass fiber.
Fig. 26. Tensile strength in 0°/90° UD carbon fiber.
Fig. 29. Tensile strength in Bidirectional carbon fiber.
Fig. 27. Structural deformation.
Fig. 30. Structural deformation.
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Flexural strength identifies the amount of strength and force a structure can withstand such that it resists any bending failures. In this unidirectional fiber, both the ends are clamped to test its bending ability, the structure is varying non-linearly as in the Fig. 19. A non-linear structure will not be suitable for a higher travel applications and the breaking point is found at 7.06 kN (See Fig. 20 and 21). 2.5.4. Case (iii): Bidirectional glass fiber From the above plot, we could see that the bidirectional glass fiber offers better tensile strength than the unidirectional fiber.
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Area where the stress acts can be seen in red color and it is not distributed throughout its area like the unidirectional fibers. Maximum tensile strength obtained is 171.297 N and the material is deformed by 0.863 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. As seen in the 0°/90° unidirectional glass fiber, the specimen is varying non-linearly on applying load. From the Fig. 22, we could see that the material tends to bend due to the applied load but the force distribution is not even throughout its structure. Since this composite belt should roll over a machine sheave, this should be good in its flexural ability. 2.5.5. Case (iv): 0° unidirectional carbon fiber From the above result, we could see that the max tensile strength obtained is 594.711 N and the material is deformed by 5.606 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. Among all the fibers we have discussed, unidirectional carbon fiber seems to offer better tensile strength and the material tends to deform instead of breaking down (See Figs. 23 and 24). Amidst all the glass fibers, the 0° unidirectional carbon fiber is varying its structure uniformly on applying the load and the maximum strength is visualized at 12.65 kN. From the Fig. 25, we could see that the center region undergoes high bending with linear variation in the structure (See Figs. 26 and 27). 2.5.6. Case (v): 0°/90° unidirectional carbon fiber From the above result, we could see that the max tensile strength obtained is 448.296 N and the material is deformed by
Fig. 31. Flexural strength in Bidirectional carbon fiber.
Fig. 32. Tensile strength chart.
Fig. 33. Flexural strength chart.
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Table 5 Data’s obtained through analysis. Reinforcement type
Tensile strength (MPa)
Deformation-tensile (mm)
Applied load (kN)
Flexural load (kN)
Unidirectional. glass (0°) Unidirectional glass (0°/90°) Bidirectional glass Unidirectional. carbon (0°) Unidirectional. carbon (0°/90°) Bidirectional carbon
166.102 110.335 171.297 594.711 448.296 332.525
1.64 0.2017 0.863 5.60 0.703 1.741
13.47 10.010 14.20 40.0 21.70 28.43
9.245 7.065 3.600 12.6541 9.643 5.892
0.703 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color. The strength required to break the material is little lesser as compared to the zero degree unidirectional carbon fiber. Carbon fibers seems to offer good flexural strength as compared to the glass fibers, but the 0° unidirectional carbon fibers offer better results than 0°/90° unidirectional carbon fiber and can be seen in the Fig. 28. 2.5.7. Case (vi): Bidirectional carbon fiber From the above result, we could see that the max tensile strength obtained is 332.525 N and the material is deformed by 1.74106 mm. Since the material is clamped at both the ends the higher stress can be visualized in the middle region shown by red color (See Figs. 29 and 30). Bidirectional carbon fibers offers a linear variation of the structure along the direction of load applied. And the maximum stress can be seen in red in color in the Fig. 31. But it can withstand only a load of 5.892 kN whereas unidirectional carbon and 0° degree unidirectional glass fiber has better bending strength comparatively (See Figs. 32 and 33). 3. Results and discussion Tensile strength and the flexural strength of the Glass fiber reinforced composites and the Carbon Fiber Reinforced Composites are shown in Tables 4 and 5. From the results, carbon fiber epoxy reinforced composites has the high strain compared to the glass fiber reinforced composites. The tensile strength of the glass fibers were almost similar and their strain ratio changes accordingly. But the carbon fiber epoxy reinforced composites has possess the highest tensile strength in all its orientation. And the 0° unidirectional carbon fiber has the highest tensile strength with higher strain ratio as compared to the other composites. The tensile strength and flexural strength of glass and carbon fiber epoxy reinforced composite is shown in the chart below. In this case, composite with 0° orientation has the higher flexural strength similar to the tension results. According to the test results, 0°/90° unidirectional and bidirectional glass fiber had the lowest tensile and flexural strength. When the composites were compared according to the tensile and the flexural strength, carbon fiber reinforced composites had better performances, because car-
bon fiber as a single filament has better mechanical properties compared to the glass fibers. 4. Conclusion In this study, mechanical properties of bi-directional and unidirectional fiber reinforced epoxy composites were investigated. To employ the fiber re-inforced composite in elevators, the composite should withstand the rope forces that has been calculated previously. Linear variation in bending of structure is required to make the composite roll around a motor sheave for traction and the proposed design of composite should be high in tensile strength since this will undergo tension during loading of passengers and goods. Unidirectional carbon fibers has the more tensile and flexural strength [N. Ozsoy*, A. Mimaro§lu, M.I. Ozsoy, 2014]. All the fibers, such as bidirectional and unidirectional glass and carbon fibers will withstand the forces since their tensile strength are greater than 50.62 KN. But comparatively, the 0° unidirectional reinforced carbon fiber composite has the high tensile strength and their flexural strength are way better amidst the other fibers and their orientations, which has the most priority in the selection of ropes in elevator. So from the above data’s, the best result of tensile and bending strength is found in 0° orientation of unidirectional carbon fiber reinforced epoxy composite comparatively with the other tested composite materials and can be employed in high rise elevator applications. References [1] N. Ozsoy*, A. Mimaro§lu, M.I. Ozsoy, 2014 ‘Comparison of Mechanical Behaviour of Carbon and Glass Fiber Reinforced Epoxy Composites’, 4th International Congress APMAS2014. [2] POP P. Adrian1, BEJINARU MIHOC Gheorghe2, 2010 ‘Manufacturing Process and Applications of Composite Materials’, Fascicle of Management and Technological Engineering, Volume IX (XIX), NR2. [3] Ettore Coggi, Milan, Italy, 1961 ‘Composite Ropes, Cords and the Like’ 13 claims (Cl. 87-1) [4] T.D. Jagannatha, G. Harish, Mechanical properties of carbon/glass fiber reinforced epoxy hybrid polymer composites, Int. J. Mech. Eng. Rob. Res. 4 (2) (2015). [5] F.C. Campbell, Manufacturing Processes for Advanced Composites, Elsevier Advanced Technology, 2004. [6] P.K. Mallick, Fiber Re-Inforced Composites, Third Ed. CRC Press. [7] J.M.L. Reis, J.L.V. Coelho, A.H. Monteiro, H.S. Da Costa Mattos, Compos. B 43 (2012) 2041.
Please cite this article as: R. Sujith Kumar, G. Swaminathan and G. Babu Loganathan, Design and analysis of composite belt for high rise elevators, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.09.063