Satellite Batteries

The pressure vessel must satisfy aerospace standards for pressurized systems, including safety factors on burst pressure. An axisymmetric model of the structure was generated with ADINA, using 1700 elements and 4000 nodes. Nonlinear analyses of the structure were performed to demonstrate that the shell meets all requirements. The predicted burst pressure has generally been about 5% below the test results. The burst failure mode is always exactly as predicted.

The most severe loading that satellites experience is generally during launch. Many components of the batteries were also critical for launch loads. Linear and nonlinear analyses of the battery, including the internal components, were performed to ensure that the battery would survive the launch environment.

A very important consideration for satellite batteries is the fracture mechanics analysis. All pressurized systems are required to have a predicted life of 4 time the service live, assuming there is a crack present in the structure which is just below the threshold for reliable detection. Satellite batteries undergo a pressure cycle during every orbit, and therefore accumulate a large number of stress cycles. This type of analysis frequently controls the design of the pressure vessel. SC Solutions performed complete fracture mechanics analyses of all components of the battery structure to ensure that there was sufficient safe life for the design missions.