Mechanical damage and crack growth in concrete
Mechanical damage and crack growth in concrete
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混凝土的机械损伤和裂纹扩展
DOI：
10.1007/978-94-009-4350-6
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
A. Carpinteri
中科院分区：
文献类型：
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作者：
A. Carpinteri
第三卷和第四卷涉及混凝土的断裂力学，强调材料测试和一般结构应用，人们认为需要进一步关注混凝土的试样尺寸和加载速率的影响。迄今为止，成功地将混凝土高度非线性裂纹扩展数据线性化的唯一标准是应变能密度理论。特别是，当样本尺寸和加载步骤或速率改变时，绘制应变能量密度因子与裂纹扩展（称为SR·曲线）的裂纹扩展阻力曲线是直线。这允许推断数据并提供有用的设计方法。本书的独特之处在于它专门讨论应变能密度理论在混凝土土木工程结构构件中的应用。详细分析了各种不同构件的混凝土应变软化行为，包括钢筋的影响。通过调用弹性卸载机制来计算每次加载增量时材料的永久损坏。这一假设在混凝土结构中是合理的，其中有效刚度主要取决于裂纹扩展速率和载荷历史。裂纹扩展数据以 SR 曲线的形式呈现，重点放在缩放样本尺寸上，仅靠缩放样本尺寸就可以将失效模式从塑性塌陷改变为脆性断裂。加载率的影响也可以通过屈服和断裂来控制失效。
Following Volumes III and IV that dealt with the fracture mechanics of concrete emphasizing both material testing and structural application in general, it was felt that specimen size and loading rate effects for concrete require further attention. The only criterion that has thus far successfully linearized the highly nonlinear crack growth data of concrete is the strain energy density theory. In particular, the crack growth resistance curves plotting the strain energy density factor versus crack growth known as the SR· curves are straight lines as specimen size and loading steps or rates are altered. This allows the extrapolation of data and provides a useful design methodology. This book is unique in that it is devoted specifically to the application of the strain energy density theory to civil engineering structural members made of concrete. Analyzed in detail is the strain softening behavior of concrete for a variety of different components including the influence of steel reinforcement. Permanent damage of the material is accounted for each increment of loading by invoking the mechanism of elastic unloading. This assumption is justified in concrete structures where the effective stiffness depends primarily on the crack growth rate and load history. Crack growth data are presented in terms of SR-curves with emphases placed on scaling specimen size which alone can change the mode of failure from plastic collapse to brittle fracture. Loading rate effects can also be scaled to control failure by yielding and fracture.