【作者】 何春林；

【导师】 邢静忠；

【作者基本信息】 兰州理工大学 ， 工程力学， 2007， 硕士

【摘要】 混凝土空心砌块取材广泛、施工方便、造价低廉，同时具有节地、节能等特点，符合环境保护和可持续发展的需要，成为我国多层建筑的主导性墙体材料。国内外研究大都以现行有关标准为依据，对砌块与砌体力学性能的试验研究较多，而对混凝土砌块力学性能的理论分析研究较少。由于混凝土材料的非线性性质，只有通过对混凝土空心砌块非线性分析，才能获得混凝土空心砌块从较小受力状态直到接近破坏的极限状态的全面认识。本文采用ANSYS软件，运用数值模拟技术对单个空心混凝土砌块的非线性力学行为进行研究，分析了影响混凝土空心砌块非线性力学行为的主要因素，为空心砌块合理设计和结构优化提供理论参考。通过对现有混凝土本构模型对比分析，选定了本文拟采用的混凝土非线性本构模型；并借助ANSYS软件完成了对钢筋混凝土板的非线性力学分析，得出变形，应变和应力分布，计算结果和实验数据对比表明，ANSYS可以较好地完成钢筋混凝土结构的弹塑性分析。利用ANSYS软件完成圆孔内腔混凝土空心砌块建模、网格划分、本构关系选择和非线性力学分析。获得了顶面均布压力作用、底面完全固定的混凝土空心砌块的变形、应交和应力分布，以及顶面的荷载位移曲线；进行了混凝土空心砌块非线性和线弹性结果的分析比对，得到了混凝土空心砌块的强度设计和评价的应力、应变等指标。研究了不同本构关系、不同混凝土强度等级和不同孔型对混凝土空心砌块非线性力学性能的影响。研究表明：利用Sargin本构关系得出的混凝土非线性有限元分析结果比较理想；随着强度等级的提高，混凝土的脆性特性明显增大，即混凝土空心砌块的非线性性能越不明显。采用强度等级较高的混凝土可提高承载力，减小变形量；对三种不同孔型的混凝土空心砌块的非线性力学性能研究发现，几何尺寸没有突变的孔型对空心砌块受力性能比较有利。更多还原

【Abstract】 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.更多还原