A7N01P-T5铝合金断裂韧度的厚度效应

Thickness effect on fracture toughness of A7N01P-T5 aluminum alloy

采用国家标准GB4161—2007对高速列车承载底架焊接结构材料A7N01P-T5铝合金型材的断裂韧度KC进行了测试和分析,测试了3种厚度母材的KC,基于能量理论和线弹性力学提出A7N01P-T5铝合金断裂韧度随试样厚度变化关系KC(B)的解析公式,并进一步采用国家标准GB21143—2007的CTOD试验对其进行验证.结果表明,该公式具有较高的精度和普适性,可用于确定不同板厚材料的KC,将公式应用于不同壁厚条件下的焊接结构的完整性评定,以此节省人力物力,并大幅度缩短焊接结构完整性评定及结构剩余寿命的计算周期.同时为各种金属材料的KC获取提供通用性的方法和参考准则.

Based on the present fracture toughness test methods for metallic materials,the fracture toughness KC of A7N01P-T5 aluminum alloy was first tested according to the national standard GB4161-2007 and the corresponded analysis was also carried out.The new analytical formula of fracture toughness,which was related to the plate thickness,was proposed based on the energy theory and linear elastic mechanics.CTOD test was conducted to verify the accuracy of the new formula.The results show that the analytical formula could be used for various plate thicknesses,and also it could provide theoretical guidance for testing fracture toughness of other metallic materials.This work could not only save manpower and material resources,but significantly reduce the calculation cycle of remaining life of structures in structural integrity assessment of welded structures.Meanwhile,it also provides general methods and reference rules for obtaining the KC of other metallic materials.