引伸药筒的应变强度计算

CALCULATION OF THE STRAINED STRENGTH FOR A CARTRIDGE CASE

火炮药筒的强度是利用冲压加工时的应变强化达到的。用常规的幂强化公式计算药筒在引伸后的强度时，数值偏低较多，原因是该公式未考虑引伸凹模锥角对强化的影响。本文经过力学推导，给出了考虑模角影响的应变强度计算公式，其计算结果与药筒实测值相符。

In general,the strensth after strain-hardening can be calculated with fair accuracy with the formula reflecting the power lawσ＝A .But the strength of the cartridge case after ironing drawing cannot be accurately calculated by this formula,because the result of calculation is lower than that reached in practice.In this paper a new formula is siven,in which the effect of the die angle to the strain-hardening is included into consideration.Agreement between the calculated value and that from practical tests proves to be satisfactory.