Stability Analysis Of Micro-laminated Composite Structure And Analysis Of The Scale Effect

The microstructure of material has a large number of inclusions, micro-cracks,imperfections and lattices. Lots of researches and experiments show that scale effects have animportant impact on the mechanical properties of the structure when the material comes intothe field of micro/nano-scale size. When the size of the structure comes into the micron oreven nanometer scale, the traditional continuous physical theory is no longer applicable due tothe existence of the size effect. The research of the modified couple stress theory has been anew domain of the continuous mechanics.The paper is divided into four chapters. The development background and developmentstatus of composite material, composite micromechanics and the couple stress theory areintroduced in chapter one. In chapter two, the basic formula of the couple stress theory andthe modified couple stress theory are introduced, and a brief introduction on the beam theoryand plate theory have been given. In chapter three, the governing equation of laminatedcomposite Timoshenko beam and composite laminated thin plate are derived by the principleof virtual work base on the modified couple stress theory, and the simplified model we need isobtained. In chapter four, the stability of the composite Timoshenko beam and compositelaminated thin plate have been analyzed through three examples. Numerical results show thatthe proposed models can capture the scale effects of bucking analysis in microstructures.