Finite element analysis is employed to investigate void growth embedded in elastic±plastic matrix material. Axisymmetric and plane stress conditions are considered. The simulation of void growth in a unit cell model is carried out over a wide range of triaxial tensile stressing or large plastic straining for various strain hardening materials to study the mechanism of void growth in ductile materials. Triaxial tension and large plastic strain encircling around the void are found to be of most importance for driving void growth. The straining mode of incremental loading which favors the necessary strain concentration around void for its growth can be characterized by the vanishing condition of a parameter called``the third invariant of generalized strain rate''. Under this condition, it accentuates the internal strain concentration and the strain energy stored/dissipated within the material layer surrounding the void. Experimental results are cited to justify the eect of this loading parameter. #

The objective of this research was to develop a new composite material/system in structural civil engineering. To use of mechanical properties of bamboo-based panel and cold-formed steel, this study composite two kind of materials above-mentioned together utilizing structural adhesives. The research developed various of bamboo/steel composite members, such as composite slabs, composite walls, composite beams and composite columns. And the paper emphasized mechanical performance of bamboo/steel composite slabs and composite beams. Experimental studies on flexural behavior of 6 composite slabs and 9 composite beams were carried out and the failure process, failure modes and failure mechanism were investigated. Experiment results indicates that the bamboo plywood and cold-formed steel can form an excellent composite cross-section; Load vs. mid-span deflection curves of composite slabs and composite beams show linear on serviceability limit state. The maximum ultimate strength of composite slabs and beams have reached 30.0 kN•m and 36.13 kN•m respectively. The study shows that bamboo-steel composite members have good prospects in building structures of China.

In order to promote building structure to be environmental friendly, light-weight and high-strength, a novel bamboo-steel composite wall is proposed. The composite wall is made up by sticking two pieces of bamboo plywood on the faces of a piece of profiled steel sheet utilizing structural glue. Taking thickness of the bamboo plywood and thickness and corrugation-height of the profiled steel sheet as variables, quasi-static tests were carried out on 5 specimens. Based on experimental phenomena and data, their earthquake resistant properties such as horizontal bearing capacity, ductility and energy dissipation and failure mechanism are analyzed. The results show that the bamboo plywood and profiled steel sheet can effectively work together, the composite walls possess wonderful seismic properties, and that changes of thickness or corrugation-height of profiled steel sheet make very sharp differences to the properties of the walls. Finally, a simplified mechanical model and calculation method for horizontal bearing capacity are proposed according to hysteresis curves within elastic range of these walls. The calculated values match well with the experimental ones.

The goal of this research is to understand the status quo and trend of research on numerical simulation of explosion and shock wave resistance of metal foam material. Methods of modelling metal foam material and numerical algorithms of explosion and shock, as well as the current advances in two aspects have been briefly reviewed. Some problems existing in numerical simualtion of explosion and shock wave resistance of metal foam material have also been pointed out. Conclusions of this research will be of benefit to study explosion and shock wave resistance of metal foam material using numerical approach farther.