直升机在机动状态下的桨叶弹击数值模拟

为了研究直升机旋翼桨叶在机动状态下的弹击损伤，在数模模拟中，预先考虑了桨叶在机动状态下的拉力、挥舞力矩、摆振力矩对弹击损伤的影响。针对某型机旋翼桨叶，采用全尺寸有限元模型进行了弹击数值模拟分析。首先使用自编Fortran程序和VABS软件计算了桨叶剖面特性；之后建立了弹性桨叶结构载荷分析模型，采用CAMRIDII软件计算了机动状态下的桨叶载荷；在此基础上，使用NASTRAN软件对桨叶进行瞬态分析，得到桨叶施加载荷的预应力状态；再使用DYTRAN软件，基于自适应接触法，模拟桨叶弹击损伤。研究表明：桨叶结构损伤程度与弹击速度是非线性关系；除了弹击点，大梁与上下蒙皮的过渡区域是二次损伤部位；桨叶抗弹击设计需要考虑结构件之间的刚度匹配问题，以达到最佳的抗弹击吸能效果与最小损伤面积。

Numerical Simulation of Helicopter Blade Bullet Penetration in Maneuvering State

In order to study the impact damage of helicopter rotor blade under maneuvering condition, in the numerical simulation, the effects of the pulling force, swing moment and shimmy moment of the blade on the impact damage were considered previous. For the rotor blade of a certain type of aircraft, the full - size finite element model was used to simulate the impact.First the profile characteristics of the rotor blade were calculated by using the Fortran program and VABS software. After that, the load analysis model of elastic blade structure was established and the software CAMRIDII was used to calculate the blade load in the state of mobility. On this basis, NASTRAN software was used to conduct transient analysis on the the blade, and the prestress state of the blade under load was simulated. Then DYTRAN software was used to simulate the damage caused by the blade bounce based on the adaptive contact method. The research shows that the damage condition of the blade is non-linear with the impact velocity. In addition to the bullet point, the surrounding structure will also be damaged when the projectile hits. The stiffness matching between the structural parts should be considered in the design of the impeller to achieve the best impact energy absorption effect and the minimum damage area.