Analysis Of State Of The Weld On Torpedo Battery Segment Which Under Pressure Based On Finite Element Method

Torpedo is important to national defense.The function of the pipe of torpedo battery section is to load the battery and other related components and connect the other section of the torpedo.Once there is something wrong in the torpedo battery section the torpedo will not work well.The weld of the pipe body is cracked during the pressure test after the pipe body is manufactured,which indicate that the strength of the pipe weld can not meet the requirements under the water pressure.In this paper,the finite element method is used to study the state of welds of the torpedo battery segment.It not only to calculate the residual stress of the weld,but also work out the stress of the weld under the pressure,in order to provide a theoretical basis of the state of the weld under pressure.The total stress on the weld is mainly composed of two parts when the pipe is under pressure test:(1)the residual stress after the friction stir welding;(2)the stress caused by the pressure on the pipe weld.Therefore,this paper study on these two aspects basing on finite element analysis.The contents and results of this paper are as follows:First of all,using APDL language to calculate the friction stir welding simulation basing on ANSYS platform.In this paper,the APDL language is used to model the simplified tube body and cycle the heat source to simulate the temperature change of the welding part during welding.And then,using the theory of thermo-structural coupling to carry out the residual force of the tail weld after the welding is completely cooled.Then,the pipe body which is under press is carried out by finite element method based on the ANSYS Workbench platform.The finite element calculation is earried out under the condition of two kinds of limit water pressure:(1)3.5MPa body surface pressure of the tube;(2)5.1 MPa body surface and cavity surface pressure.The larger results is obtained after comparison.Finally,adding the data which comes from the same part of the weld to get the total stress of it.It is obvious that it is safe because the maximum stress on the weld is less than the yield strength of the material.