behaviour strategy
6.All concrete structures are exposed to volume changes caused by hydration reactions in the early age.If the volume changes are restrained,stresses is generated which will cause cracking when it overcomes the tensile strength.As the mechanical properties of early age concrete vary with time,especially the creep degree depends on the time elapsed and the time at loading,to calculate the stress of concrete structure is a complex nonlinear problem .The finite element method (FEM) can take account of the evolution of the stiffness properties,the development of thermal strain,creep,shrinkage and so on.In this paper,a general approach for numerically simulating this type of behaviour is presented firstly.Then,how to solve this problem is introduced by the general finite element software ANSYS using the Initial Stress Method.Finally,a detailed description of an example calculation that demonstrates the potential of the numerical simulation strategy follows.
