混凝土抗拉强度动力增大因子的修正解析模型  

A MODIFIED ANALYTICAL MODEL FOR DYNAMIC INCREASE FACTOR OF TENSILE STRENGTH OF CONCRETE

作　　者：李冬[1] 高堃 金浏[1] 杜修力[1] LI Dong;GAO Kun;JIN Liu;DU Xiu-li(Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市减灾与防灾防护教育部重点实验室,北京100124

出　　处：《工程力学》2025年第2期41-53,共13页Engineering Mechanics

基　　金：北京市科技新星计划项目(20220484047);北京市自然科学基金项目(JQ22025)。

摘　　要：混凝土强度的率敏感性,是混凝土力学研究领域中的重要科学问题之一。现有混凝土动力增大因子的预测方法,仍主要以基于数据的拟合模型为主,拟合参数通常无实际物理意义,因而无法与有关混凝土率敏感性的机理解释建立数理联系。该文以混凝土抗拉强度为研究对象,基于自洽有限应力模型和牛顿运动定律的基本概念,推导建立了能够体现混凝土应变率效应机理的动力增大因子数理方程;分别基于FIB规范模型和J准则模型提出了混凝土抗拉强度动力增大因子的半解析-半经验分析方法;通过基于细观数值试验的案例分析和基于文献中试验数据的对比,验证了该文修正解析模型能够有效反映混凝土抗拉强度动力增大因子的真实物理规律。The rate sensitivity of concrete strength is one of the important scientific problems in the field of concrete mechanics.The existing prediction methods for the dynamic increase factor of concrete are still mainly based on the data fitting model,and the fitting parameters usually have no actual physical significance,thusly it cannot relate to the mechanism interpretation of the concrete rate sensitivity.This paper takes the tensile strength of concrete as the research object.Based on the basic concepts of self-consistent finite stress model and on Newton's law of motion,derived and established is the mathematical equation of a dynamic increase factor which can reflect the strain rate effect mechanism of concrete.Based on a fib specification model and a J criterion model,proposed is a semi-analytical and semi-empirical analysis method to analyze the dynamic increase factor of concrete tensile strength.Through the case analysis based on mesoscopic numerical tests and the comparison based on the test data in the literature,it is verified that the analytical model revised can effectively reflect the real physical law of the dynamic increase factor of concrete tensile strength.

关 键 词：混凝土 动态强度 抗拉强度 动力增大因子 应变率效应 

分 类 号：TU528[建筑科学—建筑技术科学]