基于局部损伤混凝土模型的混凝土动态力学性能研究

发布时间：2018-05-16 16:35

本文选题：混凝土 + KC局部损伤混凝土模型　；参考：《昆明理工大学》2017年硕士论文

【摘要】：混凝土结构除了承受静力荷载以外,不可避免承受动力荷载如地震作用、风荷载、冲击或爆炸荷载等。由于其不可预知性及发生时对结构产生的严重破坏性,让动力荷载成为影响混凝土结构设计的关键因素之一。混凝土是应变率敏感性材料,动荷载与静荷载作用下的力学特性具有不同的特征,因此在动力荷载条件下仍用混凝土静态力学参数进行计算将不能准确预测结构动态响应。充分认识混凝土材料在不同应变率下的材料特性,正确建立混凝土材料的动态本构方程对预测动力荷载下的整体结构响应至关重要。大部分研究者在有限元模拟动态荷载下钢筋混凝土结构的响应过程中没有考虑混凝土应变率效应的影响,或者是直接引用未经修正的混凝土动态强度-应变率曲线,这两种方法均不能准确定义混凝土的动态材性。本研究通过对现有的混凝土动态抗压和动态抗拉试验数据进行数据统计并与现有动态强度增长因子DIF与应变率ε曲线公式进行比较,选择了与试验数据吻合度较高的DIF-ε曲线。基于该混凝土动态材性曲线、和ANSYS/LS-DYNA显式动力有限元计算平台及KC局部损伤混凝土模型进行SHPB动态抗压和动态抗拉数值模拟,对混凝土DIF-ε曲线在有限元中的应用进行了详细探讨。
[Abstract]:In addition to static loads, concrete structures are inevitably subjected to dynamic loads such as earthquake, wind load, impact or explosion load, etc. Because of its unpredictability and serious damage to the structure, the dynamic load becomes one of the key factors that affect the design of concrete structure. Concrete is a strain rate-sensitive material, and the mechanical properties of concrete under dynamic load and static load have different characteristics. Therefore, the calculation of static mechanical parameters of concrete under dynamic load condition will not be able to accurately predict the dynamic response of structure. It is very important to correctly establish the dynamic constitutive equation of concrete material to predict the response of the whole structure under dynamic load by fully understanding the material characteristics of concrete material under different strain rates. Most researchers do not consider the influence of concrete strain rate effect in the response of reinforced concrete structure under finite element simulation of dynamic load, or directly use the uncorrected dynamic strength strain rate curve of concrete. Neither of these two methods can accurately define the dynamic properties of concrete. In this study, the existing dynamic compressive and tensile test data of concrete were statistically analyzed and compared with the existing dynamic strength growth factor (DIF) and strain rate 蔚 curve formula, and the DIF- 蔚 curve with high coincidence with the test data was selected. Based on the dynamic properties curve of concrete, ANSYS/LS-DYNA explicit dynamic finite element calculation platform and KC local damage concrete model, SHPB dynamic compressive and dynamic tensile numerical simulation are carried out, and the application of concrete DIF- 蔚 curve in finite element is discussed in detail.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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