航空发动机双层结构金属机匣的弹道试验

为研究航空发动机双层结构金属机匣在受叶片冲击时的包容性问题，利用滑膛炮试验系统对双层钛合金带不同间隙叠层靶板进行打靶弹道试验。通过28次有效的弹道试验发现:对比内层（迎弹面）、外层靶板厚度相同带间隙组合的试验结果，间隙越大靶板抗侵彻能力越差；对比不带间隙组合试验结果，内层较薄组合的抗侵彻能力强于内、外层厚度相同组合。采用商业有限元软件ANSYS/LS-DYNA对打靶试验进行了数值仿真，有限元仿真与试验结果吻合较好，并发现内层较薄组合的抗侵彻能力强于内层较厚组合，且两者均强于内、外层厚度相同组合；各个组合在没有间隙的情况下，弹道极限随叶片攻角增加而增加，但是速度曲线突增的攻角有所不同。无量纲靶厚决定了叶片冲击双层靶板的破坏模式。 

Ballistic test of double-layer metal casing of aero-engines

In order to study the containment of double-layer metal-structured casing of aero-engines under blade`s impact，the ballistic test of double-layer titanium alloy laminated target plates with different clearances was carried out by using a sliding-bore gun test system.The process of blade penetration into target plate was recorded by high-speed camera system，and the damaged targets were recovered.The penetration resistance and failure modes of different laminated target plates were studied.Through 28 effective ballistic tests，it was found that: compared with the test results of the combination with the same thickness of the inner （attack surface） and outer target plate，the larger gap indicated the worse anti-penetration ability of the target plate；compared with the test results of the combination without the gap，the anti-penetration ability of the combination with the thinner inner target plate was better than that of the combination with the same thickness of the inner and outer target plates.The ballistic test was simulated numerically by commercial finite element software ANSYS/LS-DYNA.The finite element simulation results were in good agreement with the test results.It was found that the anti-penetration ability of the combination with thinner inner target was stronger than that of the combination with thicker inner target，and both of them were stronger than that of the combination with the same thickness of inner and outer targets；in the case of no clearance，the ballistic limit increased with the increase of blade angle of attack，but the angle of attack of the sudden increase of velocity curve was different.The dimensionless target thickness determined the failure mode of the blade impacting the double-layer targets.