565 research outputs found
Statistical higher-order multi-scale method for nonlinear thermo-mechanical simulation of random composite materials with temperature-dependent properties
Stochastic multi-scale modeling and simulation for nonlinear
thermo-mechanical problems of composite materials with complicated random
microstructures remains a challenging issue. In this paper, we develop a novel
statistical higher-order multi-scale (SHOMS) method for nonlinear
thermo-mechanical simulation of random composite materials, which is designed
to overcome limitations of prohibitive computation involving the macro-scale
and micro-scale. By virtue of statistical multi-scale asymptotic analysis and
Taylor series method, the SHOMS computational model is rigorously derived for
accurately analyzing nonlinear thermo-mechanical responses of random composite
materials both in the macro-scale and micro-scale. Moreover, the local error
analysis of SHOMS solutions in the point-wise sense clearly illustrates the
crucial indispensability of establishing the higher-order asymptotic corrected
terms in SHOMS computational model for keeping the conservation of local energy
and momentum. Then, the corresponding space-time multi-scale numerical
algorithm with off-line and on-line stages is designed to efficiently simulate
nonlinear thermo-mechanical behaviors of random composite materials. Finally,
extensive numerical experiments are presented to gauge the efficiency and
accuracy of the proposed SHOMS approach
SOLID-SHELL FINITE ELEMENT MODELS FOR EXPLICIT SIMULATIONS OF CRACK PROPAGATION IN THIN STRUCTURES
Crack propagation in thin shell structures due to cutting is conveniently simulated
using explicit finite element approaches, in view of the high nonlinearity of the problem. Solidshell
elements are usually preferred for the discretization in the presence of complex material
behavior and degradation phenomena such as delamination, since they allow for a correct
representation of the thickness geometry. However, in solid-shell elements the small thickness
leads to a very high maximum eigenfrequency, which imply very small stable time-steps. A new
selective mass scaling technique is proposed to increase the time-step size without affecting
accuracy. New ”directional” cohesive interface elements are used in conjunction with selective
mass scaling to account for the interaction with a sharp blade in cutting processes of thin ductile
shells
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