Computational & Technology Resources
an online resource for computational,
engineering & technology publications
Civil-Comp Proceedings
ISSN 1759-3433
CCP: 67
Edited by: B.H.V. Topping
Paper II.2

Shape Optimization for Lifetime Increasement using Continuum Damage Mechanics

E. Schnack and W. Weikl

Institute of Solid Mechanics, Karlsruhe University, Karlsruhe, Germany

Full Bibliographic Reference for this paper
E. Schnack, W. Weikl, "Shape Optimization for Lifetime Increasement using Continuum Damage Mechanics", in B.H.V. Topping, (Editor), "Computational Techniques for Materials, Composites and Composite Structures", Civil-Comp Press, Edinburgh, UK, pp 147-160, 2000. doi:10.4203/ccp.67.2.2
In mechanical engineering we are usually concerned with dynamically loaded constructions, i.e. machinery parts. In this paper a new idea for high-cycle fatigue behaviour working with the two-grid method is presented, using one grid on the micro-level and the other one for the mesolevel. Using a homogenization technique, we develop an energy release rate formulation on the micro-grid, from which the evolution equation for increasing damage arises. The new idea is now to define the damage at the mesolevel depending on the damage at the micro-level, while controlling the stress redistribution by a modified locally coupled analysis. This leads to a new concept for shape optimization of mechanical engineering problems using the sequential quadratic programming technique.

The theoretical and numerical results are controlled by experiments using a hydropulser machine. For high quality steel an increase of lifetime by a factor of about 3 was achieved for our shape optimized notched structures compared with the ones possessing classical circular cut-outs. Therefore we can say that this concept offers a new possibility for lifetime increasement of mechanical engineering structures.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £92 +P&P)