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Researchers study turbine disc lifing
Fotigue Researchers study turbine disc lifing
Sine controller said to be fully programmable
A programme to develop the technology and knowledge required to make remaining-life predictions for low-pressure turbine rotor discs that are cracked in the blade attachment (steeple) region has begun at Southwest Research Institute, TX, USA. In-service cracking of the discs leads to costly downtime for rotor inspection and repair or replacement; there is thus a great need for accurate remaining-life predictions for cracked discs. 'The inability to predict the life of discs cracked in the steeple region is due to the inability to size steeple cracks, the lack of stress intensity distributions for the steeple geometry and the lack of an adequate failure criterion that can account for vibratory
A programmable sine controller (PSC) has been developed by U K company Derritron Electronics, for use in production, R & D and general vibration testing in a variety of industries, including automotive and avionics. The PSC unit is able to perform a range of sinusoidal tests with monitor and protection facilities built in to prevent over-testing. It is claimed to be easy to use and set up, with new tests usually programmable in under ~o minutes by resppnse to a structural questionnaire. A built-in time-elapsed clock, diagnostic and help facilities are standard. The PSC, which operates in metric or imperial units, can store up to eight programs and all test parameters can be 'locked-in' to prevent unauthorized alterations. An I E E E interface is standard, and the instrument, which requires no optional extras, is priced at under £5 ooo. Contact: J. Considine, Derritron
stresses', according to Senior Research Engineer, Andrew McMilm, who will head the research team. To overcome these problems, the Institute programme will include the development of ultrasonic crack sizing techniques using either signal amplitude or tip-diffracted wave methods. Sizing will be performed on samples of cracked discs and correlations between ultrasonic signals and crack size will be established by destructive examination. Stress analysis of the disc steeple region and generation of representative threshold fatigue crack data will be performed to develop an overall remaining-life methodology.
Andrew McMinn, Southwest Research Institute, PO Drawer 28:xo, San Antonio, TX782#4, USA.
Universal testing machine has increased capacity The model 7~ 58 universal testing machine is the second in a series of computer-based systems to be introduced by Avery Denison of Leeds, UK. This machine increases the capacity of the first model, the 715 7, from z5o to 500 kN. The computer is an integral part of the machine and serves to control its operation and to process and display data on a colour monitor. For each test it can calculate, print out or store the proof stress, ultimate tensile strength and percentage elongation. The stress/strain curve is displayed on the VDU and printed out at the end of the test.
Avery Denison Ltd, Moor Road, Leeds LS1o 2DE, UK.
Electronics Ltd, Sedlescombe Road North, Hastings, East Sussex TN34 ,XB, UK.
Tape deck tracks vibration
Avery Denison's 7158 has a 500
kN capacity
Seven materials testers ordered for composites research Seven MTS Model 88o material test systems have been ordered by Bell Helicopter Textron of Fort Worth, TX, USA. The package cost $9oo ooo and represents the largest single order MTS have received to date for the Model 88o. The systems will be equipped
238
with multi-station advanced automation packages and are to be used in a new material test laboratory which will concentrate on studies of composites. Contact: Don Grussing, MTS
Systems Corporation, Box 24012, Minneapolis, M N ::424, USA.
In an effort to optimize product reliability by in-vehicle vibration analysis, Lucas CAV Limited of Fehham, UK, are using some of the most sophisticated vibration test routines to be carried out by any engine components manufacturer. The method is straightforward on fixed test rigs, but is much more difficult to achieve on a moving vehicle. Thus the company required a high-quality FM recorder capable of recording the vibration levels which actually occur in service, so realistic settings could be applied to endurance vibration test rigs. Lucas CAV chose to use a 14channel Thorn EMI Datatech SE35oo instrumentatiorr recorder. This is one of a range of high-quality transportable instrumentation recorders offering analogue or high-density digital recording capabilities, and is available for around £x i 500 from: Thorn EMI
Datatech Limited, Spur Road, Feltham, Middlesex TWI 4 oTD, UK. Int
J Fatigue October 1986
Sine controller said to be fully programmable
A programme to develop the technology and knowledge required to make remaining-life predictions for low-pressure turbine rotor discs that are cracked in the blade attachment (steeple) region has begun at Southwest Research Institute, TX, USA. In-service cracking of the discs leads to costly downtime for rotor inspection and repair or replacement; there is thus a great need for accurate remaining-life predictions for cracked discs. 'The inability to predict the life of discs cracked in the steeple region is due to the inability to size steeple cracks, the lack of stress intensity distributions for the steeple geometry and the lack of an adequate failure criterion that can account for vibratory
A programmable sine controller (PSC) has been developed by U K company Derritron Electronics, for use in production, R & D and general vibration testing in a variety of industries, including automotive and avionics. The PSC unit is able to perform a range of sinusoidal tests with monitor and protection facilities built in to prevent over-testing. It is claimed to be easy to use and set up, with new tests usually programmable in under ~o minutes by resppnse to a structural questionnaire. A built-in time-elapsed clock, diagnostic and help facilities are standard. The PSC, which operates in metric or imperial units, can store up to eight programs and all test parameters can be 'locked-in' to prevent unauthorized alterations. An I E E E interface is standard, and the instrument, which requires no optional extras, is priced at under £5 ooo. Contact: J. Considine, Derritron
stresses', according to Senior Research Engineer, Andrew McMilm, who will head the research team. To overcome these problems, the Institute programme will include the development of ultrasonic crack sizing techniques using either signal amplitude or tip-diffracted wave methods. Sizing will be performed on samples of cracked discs and correlations between ultrasonic signals and crack size will be established by destructive examination. Stress analysis of the disc steeple region and generation of representative threshold fatigue crack data will be performed to develop an overall remaining-life methodology.
Andrew McMinn, Southwest Research Institute, PO Drawer 28:xo, San Antonio, TX782#4, USA.
Universal testing machine has increased capacity The model 7~ 58 universal testing machine is the second in a series of computer-based systems to be introduced by Avery Denison of Leeds, UK. This machine increases the capacity of the first model, the 715 7, from z5o to 500 kN. The computer is an integral part of the machine and serves to control its operation and to process and display data on a colour monitor. For each test it can calculate, print out or store the proof stress, ultimate tensile strength and percentage elongation. The stress/strain curve is displayed on the VDU and printed out at the end of the test.
Avery Denison Ltd, Moor Road, Leeds LS1o 2DE, UK.
Electronics Ltd, Sedlescombe Road North, Hastings, East Sussex TN34 ,XB, UK.
Tape deck tracks vibration
Avery Denison's 7158 has a 500
kN capacity
Seven materials testers ordered for composites research Seven MTS Model 88o material test systems have been ordered by Bell Helicopter Textron of Fort Worth, TX, USA. The package cost $9oo ooo and represents the largest single order MTS have received to date for the Model 88o. The systems will be equipped
238
with multi-station advanced automation packages and are to be used in a new material test laboratory which will concentrate on studies of composites. Contact: Don Grussing, MTS
Systems Corporation, Box 24012, Minneapolis, M N ::424, USA.
In an effort to optimize product reliability by in-vehicle vibration analysis, Lucas CAV Limited of Fehham, UK, are using some of the most sophisticated vibration test routines to be carried out by any engine components manufacturer. The method is straightforward on fixed test rigs, but is much more difficult to achieve on a moving vehicle. Thus the company required a high-quality FM recorder capable of recording the vibration levels which actually occur in service, so realistic settings could be applied to endurance vibration test rigs. Lucas CAV chose to use a 14channel Thorn EMI Datatech SE35oo instrumentatiorr recorder. This is one of a range of high-quality transportable instrumentation recorders offering analogue or high-density digital recording capabilities, and is available for around £x i 500 from: Thorn EMI
Datatech Limited, Spur Road, Feltham, Middlesex TWI 4 oTD, UK. Int
J Fatigue October 1986