Research On Small Deflection Of Thin Cylinder Shell With Initial Stress

Under working station, engineer structure and working piece's deformation could always be treated as small deformation added to existent deformation caused by initial stress. Small deformation behavior with initial stress or without initial stress has different control equations. The effects to structure's mechanical behavior caused by them are different, too. In allusion to cylindrical thin shell, how to describe the initial stress and analyze the effect brought by initial stress to piece's mechanical behavior are the problem this paper is to discuss.In chapter one, the raise of an ideology, studying about the deformation's rule attached to initial-stress configuration, the research history and actuality in domestic and overseas are narrated.In chapter two, the liner theory of elasticity solid's addiontional on initial-stress configuration is narrated, the initial stress is adopted as parameter described currently configuration, corresponding virtual principal and variation method are given, and the energy theory of balanceable stable critical condition is put forward according to the ideology of addiontional deformation on initial stress configuration.In chapter three, these theories described in Descartes reference frame are extended to as tensor equation applied in any reference frame.In chapter four, the numerical character described initial stress in cylindrical thin shell is advanced. Stress distribution is transformed from three-dimension to two-dimension. The corresponding control equation is given. The control equation and boundary condition about the addiontional small deformation's effect caused by initial stress using virtual principal theory in cylindrical reference frame. Generalized stress and strain and equivalent constitutive equation are given.In chapter five, four special problem about initial stress's effect to shell's mechanics behavior are discussed, including:(1) The numerical result and the effect imposed by circumferential initial stress numerical character on cylindrical thin shell's inherent frequency are given.(2) The numerical result and the critical value's effect imposed by circumferential initial stress numerical character on cylindrical thin shell beard the press at axis.(3) The inflectional form and the critical value's effect imposed by circumferential initial stress character on cylindrical thin shell beard the thrust at axis, accelerating upwards erect.(4) The deformational rule's effect imposed by circumferential initial stress character on cylindrical thin shell beard the impact side.There is little report about these problems. They have important engineering background.