铝合金型材融合口材料疲劳极限测定

Fatigue Limit Test of Fusion-mouth Material of Extruded Aluminum Alloy Profile

为了测试口形铝合金型材融合口处材料的疲劳极限,针对型材尺寸、形状和融合口位置的特殊性——不能设计成符合现有规范的标准疲劳试样形状,设计了L形缺口试样及其疲劳试验夹具。通过有限元模拟试验载荷、仿真试样应力分布,应用数值回归的方法求解出最大应力值,确立了试验载荷与L形缺口试样疲劳应力之间的函数关系。利用设计的试样和夹具进行升降法试验,测得了一种口形铝合金型材融合口处材料的疲劳极限,并对试样进行了断口分析。

In order to determine fatigue limit of fusion-mouth material of extruded aluminum alloy,the L-shaped notched specimens and their fixture were designed under the circumstance that those materials might not be designed as the normal standard fatigue specimens due to their special positions and sizes.Firstly,stresses on different locations of the tested L-shaped notched specimens were solved using finite element method.Then,the maximum stresses were approximated by means of the numerical regression method.Thus,the relationship between test load and fatigue stress might be explained by an equation.In order to determine the fatigue limit of the located-in-fused-mouth materials of a kind of extruded aluminium alloy profiles,an up-and-down program was also tested for the designed L-shaped notched specimen by designed fixture,and the fracture samples were also analysed.