Nonlinear Finite Element Analysis On Shear Behaviors Of High-strength Reinforced Concrete Masonry Shear Wall

According to the tested compressive specimens of high strength concrete small-sized hollow block masonry, the mechanical property of concrete hollow block masonry were studied, including destructive characteristic, compressive strength, deformability, stress-strain relation, elastic modulus, Poisson ratio. Study on calculation procedure of fundamental performance index.For preferable known the shear behavior of high strength concrete small-sized hollow block masonry, On the basis of some principal theory of nonlinear finite element analysis, the shear behaviors of eight different constructional measurements and different structural shapes reinforced masonry block shear walls have been analyzed. The principal stress 1 distribution, X-Y shear distribution, crack distribution and appearance sequence of walls with holes and deformation behaviors of different walls were studied. The effects of reinforced concrete hollow-block shear behavior with different ratio of grout for concrete, different strength of the core columns and different sizes of scaled holes were compared.The main studies and conclusions are as follows:1. The experimental results indicate that the first crack coefficient of high strength masonry is major, cracks become later in company with the aggrandizement of bedding core ratio and the advance of core column concrete strength level, crack factor dispersed over 0.70～0.80.2. The new formulas for calculating compressive strength and modulus of elasticity of masonry panels are presented, and the value of poisson ratio is obtained. Reasonably good agreement has been found between the calculating using new formula and experiment results and calculation suitable.3. The finite element analysis results show that the more greater of opening rate of the wall, the more smaller of the wall stiffness, the more easier to crack; With the increasing of the opening rate, cross-section flexural tensile stress( Z1 increase of 64% than Z3), bending compressive stress( Z1 increase of 70% than Z3) and the stress of the corner -hole( Z1 increase of 56% than Z3 ) are significantly increased which lead to the initial cracks of the wall. 4. With the greater of the opening rate of the wall, the sooner the cracks appear, the initial location of the cracks were changed. openning rate of 27.1 percent of the wall resulting in initial cracks at oblique angle, opening rate of 9.4 percent of the wall resulting in initial cracks at the bottom of the wall.5. With the increasing of the ratio of grout for concrete and the strength of the core columns, the shear capacity of block walls improved obviously (H5 increase of about 50% than H1), the limit displacement of the walls are increased significantly (H5 increase of about 52% than H1), the overall ductility of the walls are also improved so as to avoid of the brittle damage, and the walls safety reserves are improved.