浮空器管材结构连接方式比较及拉伸强度分析

浮空器结构件如吊舱、过渡架及推进支架等多采用金属管材连接。目前,浮空器管材结构连接缺乏使用工况下极限值实测数据,材料及连接方式选择的理论支撑尚有不足。据此,对常用管材的不同连接方式进行比较及断裂分析。研究中铝合金和钛合金管材分别采用螺接及焊接的方式进行连接,测试样品的力学性能并结合仿真分析验证其断裂原因。结果表明:TA1钛合金管材采用焊接连接方式,相对螺接方式连接强度提高 87.9%；6061铝合金管材采用螺接连接方式,相对焊接方式连接强度提高 39.3%。2A12铝合金管材焊接连接强度优于螺接连接强度。同时,分析断裂原因发现,管材形变是影响焊缝连接强度的重要因素；应力集中易发生在管材端部连接处,导致端部焊缝发生断裂；管材形变会使母材断裂时伴有撕裂现象,进一步降低管材的最大连接强度。

Comparison and Tensile Strength Analysis of Connection Modes of Aerostat Pipe Structure

The structural components of aerostat, such as pods, transition, propulsion support, etc, are mostly connected by metal pipes. The connection of aerostat pipe structure lacks actual measured data of limit values under operating condi-tions, and there is not enough theoretical support in the selection of materials and connection modes at present. Different connection modes of common pipes should be compared and analyzed for fracture. The aluminum alloy and titanium al-loy pipes are connected by screw and welding modes, respectively. Their physical properties are tested and simulated anal-ysis is performed to verify the reason of fracture. The results show that compared with the screw connection, the welding mode improves the connection strength by 87.9% for TA1 titanium pipes. Compared with the welding mode, the screw connection improves the connection strength by 39.3% for 6061 aluminum alloy pipes. The welding connection strength of 2A12 aluminum alloy pipes is better than their screw connection strength. Meanwhile, it is found that the pipe deforma-tion is a critical factor affecting the connection strength of welding pipe. Stress concentration is easy to occur at the joint of pipe ends, leading to cracks in the welding line of the ends. The pipe deformation results in tearing phenomenon when the base material is fractured, and further lowers the maximum connection strength of pipes.