Shock Response of NASA ShockSat from Explicit Dynamics Finite Element Analysis

Shock is a persistent technical challenge for spacecraft and launch vehicle systems. The modeling and simulation of shock events has been an active area of interest for many years. Shock testing has its own challenges, primarily related to suitable experiment design, acquisition of quality data, and proper physical interpretation. Explicit dynamics finite element analysis (FEA) has been previously shown to successfully predict and interpret the shock response of various systems. Here, this technique was applied to NASA ShockSat as a case study of a spacecraft-like system. Shock tests from the original ShockSat experimental program were directly simulated and compared to measured data. Analysis of both datasets presented useful insights into the shock propagation through such a system, emphasizing the underlying physics of wave propagation. The merits and limits of the simulations are discussed, as is their relation to current, industry-standard practices. Explicit dynamics simulations were found to be in excellent agreement with data measured throughout the ShockSat structure. Notable predictive accuracy was achieved despite employing low-effort modeling, indicating that complex joint behavior does not always occur.