钛合金环肋结构焊接应力变形与承载能力仿真分析

Simulated Analysis of Welding Stress/Deformation and Carrying Capacity of Ring-Stiffened Cylindrical Structure of Titanium Alloy

环肋圆柱壳结构抗压能力强,组焊过程方便。但焊接通常带有残余应力与变形,对该类结构的承载能力造成不利影响。本文采用有限元仿真方法,对钛合金环肋圆柱壳结构进行了纵缝焊接—环缝焊接—肋骨焊接—外压承载的全流程模拟。研究发现,焊接完成后焊后等效米塞斯应力接近材料屈服强度,对于大型结构而言,总变形相对较小,最大为17.23 mm。在承载压力从0加载到20 MPa的过程中,结构的变形呈现近似线性变化,结构均能够很好地承受载荷,但随着压力持续增大,应力水平随之升高,结构开始出现非线性的变形趋势。在无焊接缺陷存在的情况下,残余应力的存在对结构的承载影响不显著。研究结果为后续该类型结构的承载水平提供一定的技术参考。

The ring-stiffened cylindrical shell structure has strong pressure resistance,convenient assembly and welding process,and is widely used in the industry.However,welding usually involves residual stress and deformation,which may have a certain impact on the load-bearing capacity.Using the finite element analysis method,the full process of welding and pressure bearing was simulated on the titanium alloy of ring-stiffened cylindrical shell structure.It was found that the equivalent Mises stress is close to the yield strength of the material after welding,and the total deformation was small,with a maximum of 17.23mm.For simulating actual pressure,the deformation of the structure shows an approximately linear change when the pressure is loaded from 0 to 20MPa.The structures can bear the load well.As the pressure continues to increase,the stress level increases,and the model will begin to appear nonlinear deformation trend.It was found that the presence of residual stress has no significant impact on the load-bearing capacity of the structure.Therefore,by analyzing the welding stress/deformation and carrying capacity of the structures,the technical support is provided for load-bearing level.