Development of multi-physics numerical simulation model to investigate thermo-mechanical fatigue crack propagation in an autofrettaged gun barrel  

作　　者：Naveed Hussain Faisal Qayyum Riffat Asim Pasha Masood Shah 

机构地区：[1]Department of Mechanical Engineering,University of Engineering and Technology,Taxila,Pakistan [2]Institut für Metallformung,Technische Universitat Beragakademie,Freiberg,Germany

出　　处：《Defence Technology（防务技术）》2021年第5期1579-1591,共13页Defence Technology

基　　金：the DAAD Faculty Development for Ph.D.Candidates(Balochistan);2016(57245990)-HRDI-UESTP’s/UET’s funding scheme in cooperation with the Higher Education Commission of Pakistan(HEC)for sponsoring the stay at IMF TU Freiberg,Germany.

摘　　要：In this research,a detailed multi-physics study has been carried out by numerically simulating a solid fractured gun barrel for 20 thermo-mechanical cycles.The numerical model is based on thermal effects,mechanical stress fields and fatigue crack mechanics.Elastic-plastic material data of modified AISI 4340 at temperatures ranging from 25 to 1200℃and at strain rates of 4,16,32 and 48 s^(-1) was acquired from high-temperature compression tests.This was used as material property data in the simulation model.The boundary conditions applied are kept similar to the working gun barrel during continuous firing.A methodology has been provided to define thermo-mechanically active surface-to-surface type interface between the crack faces for a better approximation of stresses at the crack tip.Comparison of results from non-autofrettaged and autofrettaged simulation models provide useful information about the evolution of strains and stresses in the barrel at different points under combined thermo-mechanical loading cycles in both cases.The effect of thermal fatigue under already induced compressive yield due to autofrettage and the progressive degradation of the accumulated stresses due to thermo-mechanical cyclic loads on the internal surface of the gun barrel(mimicking the continuous firing scenario)has been analyzed.Comparison between energy release rate at tips of varying crack lengths due to cyclic thermo-mechanical loading in the non-autofrettaged and autofrettaged gun has been carried out.

关 键 词：Steel AUTOFRETTAGE Gun barrel Crack propagation Thermo-mechanical fatigue Numerical simulation Residual stress dissipation 

分 类 号：TJ303[兵器科学与技术—火炮、自动武器与弹药工程]