机匣包容试验的叶片根部爆破飞断方法

Research on Fan Blade Root Explosive Cutting Method for Casing Containment Test

在航空发动机包容试验中,为满足叶片在根部失效的要求,设计了基于爆破切割技术的叶片根部飞断试验方法。通过平板静态爆破试验确定了柔爆索的切割能力,并使用柔爆索进行了真实叶片的静态爆破试验。在MTS拉伸试验机上对爆破切割后的损伤叶片进行了静拉伸试验,确定了损伤叶片的剩余强度为50~56 kN。按照静态爆破试验获得的开槽尺寸在叶片根部开槽并敷设柔爆索,采用树脂胶固定后,在立式转子试验器上采用遥控触发的方式进行了真实叶片旋转状态下的飞断试验。结果表明:在叶片两侧加工4 mm深沟槽并敷设柔爆索爆破后,叶片被柔爆索切割,并在预定飞断转速下失效飞出。飞断截面断口显示叶片中段被柔爆索的金属射流完全切断,前后缘在离心载荷作用下拉断,爆破作用没有对叶片产生附加动能,成功实现了叶片在预定转速下的根部断裂失效。

In the aeroengine containment test,the fan blade is required to be cut off at the root section,a method based on explosive cutting technology was designed to meet the requirement.First of all,the cutting capability of the Flexible linear shaped charge(FLSC)was confirmed by the static plate explosive test,and then the real fan blade static explosive test was carried out subsequently.Static tensile test was conducted on the damaged blade after explosive cutting using an MTS tensile test machine,the residual strength of the damaged blade was determined to be 50~56kN.According to the slot size obtained from the static explosive test,the blade was slotted at the root section and the FLSC was fixed by resin adhesive,then explosive blade-off test under rotating conditions was conducted on a vertical spin rig by remote control triggering.The results show that after machining a 4-mm wide slot on both sides of the fan blade and laying the FLSC,the fan blade was cut off by FLSC at the predetermined rotational speed;The fracture surface shows that the middle part of the blade root was cut off by metal jet of the FLSC,then the leading and trailing edge of the blade were fractured by centrifugal load,the explosive effect did not generate additional kinetic energy on the blade,successfully achieving root fracture of the blade at the predetermined speed.