The Nonlinear Mechanical Behavior Of The Concrete Hollow Block

Concrete hollow block, which is an extensive convenient material, easy to be constructed and lower cost, with the need of sustainable development strategy and environment protection policy such as land saving and energy saving, has become one of the most competitive construction materials in masonry building construction in our country. Based on the current standards, most of the national and international research is about test research of mechanical properties. Less attention has been paid on the theory research of the mechanical properties. Due to the nonlinear property of concrete material, nonlinear analysis of concrete hollow block can lead to a fully comprehension of the entire process from small loading status to nearly damage limit state.In the paper, based on ANSYS software, nonlinear analysis of mechanical properties of one piece of hollow concrete block has been done by FEA simulation. Related factor which influenced the property of the concrete hollow block has been considered, and some useful suggestions for feasible design and structural optimization are presented. Based on the comparison and analysis of current concrete constitutive models, a feasible model was chosen for present study. Nonlinear analysis of a reinforced concrete slab has been completed by using ANSYS software, deformation, strain and stress distribution has been obtained. Comparison with the test data, it is proved that ANSYS is capable of elastic-plastic analysis of reinforced concrete structure.Nonlinear mechanical property of concrete hollow block with circular cavity, including modeling, mesh pattern and constitutive relations selection, has been fulfilled. With uniform pressure on top, bottom fully fixed, the deformation, strain and stress distribution, and load-displacement relationship of the top surface of a concrete hollow block is obtained. Comparison between nonlinear and linear analysis has been presented, and corresponding design strength index and evaluation of the stress and strain has been given.The influence factors, such as constitutive relationship, material strength and hole shape of concrete hollow block, to nonlinear mechanicsproperty has been researched. Research shows that Sargin constitutive relationship is more applicable to be used in nonlinear finite element analysis. With higher grade of strength, brittle property becomes more significance, i.e. nonlinear property becomes less obvious. Higher grade concrete can increase load allowance, and decrease deformation. Nonlinear analysis of three kinds shape hole in hollow block shows that circular hole with no sharp change of shape is more favorable.