Study On Nonlinear Finite Analysis Method Based On Layered Shell Model Of Hollow Floor Wall Structure

Cast-in-situ concrete hollow floor and reinforced block masonry shear wall havethe similar material characteristics, the respective internal holes of discontinuity. Thedifference is that reinforcement block masonry shear wall pour concrete in the hollowhole, while the floor has the hollow hole. At present, the existing literature often usethe generation of beams or fine modeling to simulate it, the effect is not very ideal.Therefore, this article is based on layered characteristics of layered shell,bysetting the continuous hollow "layer" or filling core layer to simulate the continuousholes or filling core concrete,at the same time by adjusting the position of the layer inthe thickness direction,guarantee the bending stiffness of board or wall in theout-of-plane is equal,thus realize accurate simulation of the out-of-plane stress for theconcrete hollow floor and reinforced block masonry shear wall,get the followingconclusion:(1)Through the calculation of stiffness reduction factor in X and Y for hollowfloor with different hole rate,the cross-section stiffness parallel to the tube is less thanit in vertical direction of tube. stiffness ratio of the two with the hole rate at0.3to0.5is within the scope of1.2to1.4, it can be regarded as isotropic plate to simplify thecalculation.(2)Considering the hollow characteristics of cast-in-situ concrete hollow floor,this paper puts forward layer shell model,the suitable "hollow" layer for cast-in-situconcrete hollow floor and filling core layer for reinforced block masonry shear wall,the specific Settings are as follows:①By setting two continuous hollow "layer" stripe along the neutralaxisymmetric, namely its elastic modulus is set to a small value;②The guarantee the condition of cast-in-situ concrete hollow floor has the samehollow rate,by adjusting the distance between "hollow layer" stripe, making theout-of-plane stiffness in computing directions for layered shell element equals withthe actual hollow floor.③Considering the isotropic loading characteristics of hollow "layer" for cast-in-situ concrete hollow floor,"the hollow layer" can be set up according to theisotropic material. In addition to the different material properties are adopted tosimulate the filling core layer, the filling core layer for reinforced block masonryshear wall is same with "hollow layer".(3) Using Marc finite element analysis program, successively modeling thewhole test of five piece of cast-in-situ concrete hollow floor in literature [48] andthree slices of reinforced block masonry shear wall in literature [70,71]. Bycomparing the location of plastic zone in board or wall and carry out, such as load-displacement curve, reinforcement yield complex nonlinear dynamics behavior,calculation results is good agreement with test results, shows that the model ispractical, can be used for engineering design and analysis.