A Fracture Mechanics Approach to Creep Crack Growth
A Fracture Mechanics Approach to Creep Crack Growth
复制标题
DOI：
10.1520/stp33943s
复制
发表时间：
1976
期刊：
影响因子：
--
通讯作者：
J. Landes;J. Begley
中科院分区：
文献类型：
--
作者：
J. Landes;J. Begley
采用断裂力学方法研究了高温蠕变裂纹扩展。裂纹扩展速率与C*-参数，这是一个能量速率线积分。对于在稳态蠕变范围内符合非线性应力和应变率关系的材料，特别是那些可以适当理想化为纯粘性（可忽略的弹性和瞬态蠕变效应）的材料，C* 表征裂纹尖端应力和应变率场。在1200°F（920 K）的蠕变范围内对盘状高温合金进行了裂纹扩展速率试验。两个试样的几何形状进行了测试，一个中心裂纹面板和一个紧凑的几何形状，建立这种方法的几何形状的独立性。结果表明，裂纹扩展速率与C* 积分相关，而其他参数（K和名义应力）未能充分表征裂纹扩展速率。
A fracture mechanics approach was used to study high-temperature creep crack propagation. Crack growth rates were correlated with the C*-parameter which is an energy rate line integral. For materials conforming to a nonlinear stress and strain rate relationship in the steady-state creep range, specifically, those which can be properly idealized as purely viscous (negligible elastic and transient creep effects), C* characterizes the crack tip stress and strain rate fields. Crack growth rate tests were conducted in the creep range on a discaloy superalloy at 1200°F (920 K). Two specimen geometries were tested, a center cracked panel and a compact geometry, to establish the geometry independence of this approach. The results showed that crack growth rate correlated with the C*-integral, while other parameters (K and nominal stress) failed to adequately characterize crack growth rate.