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液压支架中缸体是以焊接方式连接,那么焊缝位置的选择对于中缸体的使用寿命具有重要的影响。这样笔者分析了不同位置焊接接头的受力特点、应力强度因子以及与其相关的裂纹扩展速率(寿命评估)等断裂参数。通过不同位置焊接接头的有限元分析可知:焊接接头在中缸体中间时对压力的敏感性较强。应力强度因子的计算结果表明:对两种位置焊接接头的应力强度因子值的比较可以发现,焊接接头在中缸体中间时其应力强度因子值小于在中缸体端部时的应力强度因子值,说明了焊接接头在中间位置时抗疲劳和断裂能力较强。裂纹扩展速率试验结果表明:热影响区裂纹扩展速率大于焊缝的裂纹扩展速率,因此裂纹扩展沿着熔合线扩展的可能性更大。
Hydraulic bracket in the cylinder is connected by welding, then the choice of weld position in the life of the cylinder has a significant impact. In this way, the authors analyzed the stress characteristics, stress intensity factors and the fracture parameters such as crack propagation rate (life assessment) related to the welded joints at different locations. Through the finite element analysis of welded joints in different positions, we can see that the welded joints are more sensitive to pressure in the middle of the cylinder. The calculation results of stress intensity factor show that comparing the stress intensity factor values of welded joints at two locations, it can be found that the stress intensity factor of welding joint in the middle of cylinder is less than the stress intensity factor at the end of middle cylinder , Shows that the welded joints in the middle position fatigue resistance and fracture ability. The experimental results of crack growth rate show that the crack growth rate in the heat affected zone is larger than the crack growth rate of the weld, so the crack propagation is more likely to expand along the weld line.