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Comment on ‘A general doubly curved laminated shell theory’
Composite Slructurrs 34 ( 1996) 3.59 Copyright 0 1996 Elsevier Science Limited Printed in Great Britain. All rights reserved (3263-X223/96/$ I5.00 ELSEVIER
0263-8223(95)00157-3
Letter to the Editor Comment on ‘A general doubly curved laminated shell theory” Menahem Baruch Faculty of Aerospace Engineering,
Technion, Haifa 32000, Israel
clear that the stiffness coefficients of a ‘doubly curved laminate shell’ will vary with the coordinates of the shell and that the theory for them cannot be ‘general’. It is worthwhile to repeat the statement* ‘The stiffness coefficients needed for the analysis of a laminated structure have to be calculated only after taking into account the process which can be used to build the structure’.
In their paper’ Ossadzow, Muller and Touratier presented an erudite general doubly curved laminate shell theory. Their numerical examples constitute of static calculations for laminated rectangular plate and laminated cylindrical circular shell. However, Ossadzow, Muller & Touratier’ did not provide general expressions for the stiffness coefficients of the doubly curved laminated shell. This had to be expected because these expressions cannot be provided without knowledge of the exact geometry and the suitable manufacturing process of the laminated shell.2 In Ref. 2 it is shown that laminated rectangular plates and laminated cylindrical shells can be manufactured to possess constant stiffness coefficients. It is shown there also that for a complete conical frustum build by using a suitable filament winding process:2 ‘The stiffness coefficients of a laminated conical shell vary always and are functions of the coordinates of the shell.’ Khatri & Bardel” found that this is true also for the case of laminated open conical shell panels built by using a different manufacturing process. It is
REFERENCES Ossadzow, C., Muller, P. & Touratier, M., A general doubly curved shell theory. Composite Structures, 32 (1995) 299-312.
Baruch, M., Arbocz, J. & Zhang, G. Q., Laminated conical shells - considerations for the variations of the stiffness coefficients. Technical Report LR-671. Faculty of Aerospace Engineering, Delft University of Technology, Holland, April 1992 (also, Proceedings of the 35th AIAAIASMEIASCEIAHSIASC Structures, Structural Dynamics and Materials Conference. Hilton
Head, SC, 1994, pp. 2505-16). Khatri, K. N. & Bardell, N. S., The variation of the stiffness coefficients for laminated open conical shell panels. Composite Structures, 32 (1995) 287-92.
359
0263-8223(95)00157-3
Letter to the Editor Comment on ‘A general doubly curved laminated shell theory” Menahem Baruch Faculty of Aerospace Engineering,
Technion, Haifa 32000, Israel
clear that the stiffness coefficients of a ‘doubly curved laminate shell’ will vary with the coordinates of the shell and that the theory for them cannot be ‘general’. It is worthwhile to repeat the statement* ‘The stiffness coefficients needed for the analysis of a laminated structure have to be calculated only after taking into account the process which can be used to build the structure’.
In their paper’ Ossadzow, Muller and Touratier presented an erudite general doubly curved laminate shell theory. Their numerical examples constitute of static calculations for laminated rectangular plate and laminated cylindrical circular shell. However, Ossadzow, Muller & Touratier’ did not provide general expressions for the stiffness coefficients of the doubly curved laminated shell. This had to be expected because these expressions cannot be provided without knowledge of the exact geometry and the suitable manufacturing process of the laminated shell.2 In Ref. 2 it is shown that laminated rectangular plates and laminated cylindrical shells can be manufactured to possess constant stiffness coefficients. It is shown there also that for a complete conical frustum build by using a suitable filament winding process:2 ‘The stiffness coefficients of a laminated conical shell vary always and are functions of the coordinates of the shell.’ Khatri & Bardel” found that this is true also for the case of laminated open conical shell panels built by using a different manufacturing process. It is
REFERENCES Ossadzow, C., Muller, P. & Touratier, M., A general doubly curved shell theory. Composite Structures, 32 (1995) 299-312.
Baruch, M., Arbocz, J. & Zhang, G. Q., Laminated conical shells - considerations for the variations of the stiffness coefficients. Technical Report LR-671. Faculty of Aerospace Engineering, Delft University of Technology, Holland, April 1992 (also, Proceedings of the 35th AIAAIASMEIASCEIAHSIASC Structures, Structural Dynamics and Materials Conference. Hilton
Head, SC, 1994, pp. 2505-16). Khatri, K. N. & Bardell, N. S., The variation of the stiffness coefficients for laminated open conical shell panels. Composite Structures, 32 (1995) 287-92.
359