中文摘要：

针对速射火炮发射过程中高温高压高速火药燃气对身管应力的影响,分析连发过程中在火药燃气压力和热应力的冲击作用下,身管内应力和产生的塑性变形.基于有限元分析方法,建立了速射火炮身管截面的有限元模型,采用直接耦合的方法进行求解.得到塑性变形仅局限于基体紧贴铬钢交界面的薄层内（约0.467 mm厚）,随着连发数的增加塑性变形也在增加,并逐渐趋于稳定,这一薄层内存在最大值为470M Pa的等效残余应力的结论.在残余应力的作用下,冷却后第1发薄层内发生了反向屈服塑性变形,最大等效残余应力减小了50%;残余应力可以明显地削弱热应力,有利于身管内壁应力的稳定.

英文摘要：

In order to study the influence of high-temperature,high-pressure and high-speed propellant gas on barrel stress when shooting,analysis on stress of barrel and the plastic deformation were conducted under the pressure of powder gases and thermal stress caused by continuous emission process. The finite element model of rapid-firing gun was established and the direct coupling method was employed.The conclusion was that the plastic deformation happened only inside the thin layer of base near chromium steel interface（about 0.467 mm thickness）,and with the accumulation of continuous emissions plastic deformation increased and became stable,the maximal equivalent residual stress was 470 MPa existing in the thin layer.Under the influences of residual stress,reverse yielding plastic deformation happened in the thin layer during the first shot after cooling,and the maximal equivalent residual stress reduced by about 50%;the residual stress could obviously weaken the thermal stress which made stable for barrel stress.