Study on mechanical character of armature and rail with non-rectangular cross section in EML

How to raise launching efficiency and prolong working life are the key bottleneck problems in applying the electromagnetic launch (EML) technology to the military and civil use in future. During the launching process, control of rail deformation in a small range is very important for successful launch. Besides the rail support and containment, the shape of rail´s cross section has significant influence on its deflection under EM force load. Rectangular cross-section rails are most commonly used in railguns. However, some non-rectangular cross-section rails show performance improvement. We investigate some of these. We derive the expression for moment of inertia for several rails with non-rectangular cross section, and compare their resistance to bending with those of rectangular rails. Using Matlab software, we make numerical simulations to study the effect of the rail´s width, height, the inner radius of rail with curved surfaces, and the angle on the rail deflections. The mechanical behaviors of solid armatures, matching with non-rectangular cross section rails, are also investigated by using finite element analysis software LS-DYNA. The results indicate that non-rectangular rails maybe a good choice for future railgun weapons if adequate machining precision can be obtained.