Jong H. Kim is Senior Engineer for the Agency for Defense Development (ADD) in Daejeon, South Korea. Kim and other members of the Aircraft Structural Team are responsible for, among other things, improving the survivability of airframes so that aircraft will be able to return to base after being hit by enemy fire. The primary method of assessing design alternatives in the past, live fire testing, is so expensive and time consuming that aircraft could not be tested for all of the likely damage scenarios.
Challenge:ADD needs to evaluate various wing fuel tank designs for their ability to withstand a high velocity projectile impact. Their goal is to predict and quantity the damage from impact so that subsequent survivability analysis, such as residual strength and structural/flutter stiffness can be performed on the remaining structure. This also provides understanding of how the aircraft should be flown to enable it to safely return to base. In order to accomplish these objectives, it is necessary to simulate the very complex phenomena of hydrodynamic ram which occurs when a projectile impacts a structure containing fluid and penetrates it or detonates near it to produce a blast wave.
Solution:Patran, MSC Nastran, Flightloads, and Dytran finite element analysis software
Benefits:ADD has demonstrated the ability to simulate the damage to the airframe caused by the penetration and detonation of a projectile. This is expected to reduce the amount of live fire testing required and to make it possible to evaluate the effect of far more damage scenarios.