温度对结构钢材裂纹尖端张开位移(CTOD)的影响分析  

INFLUENCE OF LOW TEMPERATURE ON CRACK TIP OPENING DISPLACEMENT (CTOD) OF STRUCTURAL STEEL

作　　者：王元清[1] 武延民[1] 石永久[1] 江见鲸[1] 

机构地区：[1]清华大学土木工程系,北京100084

出　　处：《工程力学》2006年第4期74-78,共5页Engineering Mechanics

基　　金：国家自然科学基金项目(50078029)

摘　　要：裂纹尖端张开位移(CTOD)与钢材的弹性模量、屈服强度、几何条件和荷载大小等因素有关。结构钢材的相关力学指标随着温度发生变化,因此温度变化也会改变CTOD的数值。从含穿透缺口无限大受拉平板的Dugdale-Barrenblett模型(D-B模型)出发,推导出了温度对裂纹尖端张开位移影响规律的基本公式,并把分析进一步扩展到含跨中裂纹的三点弯曲试样。并对带跨中裂纹的三点弯曲试样进行了有限元分析和低温试验,其结果和公式进行了对比。结果表明,CTOD值随着温度降低而减小,温度对CTOD的影响程度与裂纹尖端的塑性发展程度有关。Crack tip opening displacement （CTOD） is related with Young＇s modulus, yield strength, geometrical shape, loading conditions and so on. It has been shown that many properties of structural steel varies with temperature, so the change of temperature will also change the value of CTOD. Tensioned infinite plate with a center crack is used to derive the equation for the variation of CTOD with temperature using Dugdale and Barrenblett＇s model （D-B model）. The analysis is extended to three points bending specimen with a center crack. Finite element calculations and experimental investigations for three-point bending specimen at low temperature were carried out, and the results are compared with the theoretical prediction. Results show that CTOD decreases as temperature drops, and the influence of temperature is related with plasticity status at the crack tip area.

关 键 词：温度 屈服强度 裂纹尖端张开位移 D-B模型 有限元 低温试验 

分 类 号：TU313[建筑科学—结构工程]