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混凝土框架抗火分析与计算研究
论文下载 钢筋混凝土楼板火灾反应数值计算模型 摘 要:基于退化壳原理,考虑火灾下板壳截面的不均匀温度场分布而引入分层模型,同时在每分层上考虑材料在不同温度下的热力弹塑性本构关系,建立了火灾下钢筋混凝土板壳结构的有限元数值计算模型。另外,通过全拉格朗日方法考虑了大位移的几何非线性影响。最后通过一钢筋混凝土板在高温下的试验进行了验证,并分析了配筋率和保护层厚度的影响。结果表明:提出的火灾下钢筋混凝土壳单元数值计算模型的计算结果与试验结果吻合较好,可以用来分析火灾下钢筋混凝土框架结构楼板的反应。
火灾下空间混凝土框架结构的反应分析与模拟 摘要:根据作者开发并经过试验验证的纤维梁单元模型和分层壳单元模型,通过考虑他们之间的协调关系,建立了考虑楼板的空间混凝土框架结构火灾反应数值模型,并通过作者开发的火灾反应分析系统RCFire,实现了整体结构的火灾反应分析。纤维梁单元模型和分层壳单元模型均通过在截面上进行细分,从而考虑了不均匀温度场及材料非线性的影响。通过对一个具体框架火灾反应的分析,探讨了整体结构火灾反应的规律,为结构设计人员提高建筑结构的火灾安全提供参考。 Fiber
beam element model for the collapse simulation of concrete structures
under fire, Abstract: In order to analyze and
simulate the collapse of reinforced concrete (RC) elements under fire,
a novel numerical model based on the fiber beam model is proposed in
this paper. By dividing the cross section of beam element into many
small concrete and steel fibers and assigning different materials to
each fiber, this model can consider the non-uniform temperature distribution
across the section and simulate the behavior of cracking or crushing
for concrete and yielding for steel. The explicit tangential stiffness
matrix is deduced for proposed fiber beam with Total Lagrangian (TL)
description, and the incremental equilibrium equations are also established.
Finally, the proposed fiber model is validated by comparing with various
experimental results.
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