Dynamic Drop Tower Impact Testing Principles for Consolidated Battery Tubs
Dynamic drop tower testing validates consolidated battery tub impact energy absorption, preventing cell intrusion and thermal runaway under vertical shock.
Structural Pack Design
Meaning
Replacing the traditional chassis frame with a load-bearing energy storage unit defines a modern approach to vehicle construction. Structural pack design eliminates the traditional frame rails by making the battery box stiff enough to connect the front and rear axles. This approach reduces the mass of the vehicle and improves the handling.
The cells themselves are often bonded to the case to contribute to the overall rigidity.
Load Path
Forces from the suspension and the road travel through the battery housing instead of around it. A structural pack design requires sophisticated simulation to ensure that the thousands of individual cells are not crushed by the twisting of the car. Honeycomb or ribbed internal structures distribute these stresses across a wide area.
This integration allows for a simpler and lighter body-in-white.
Volumetric Efficiency
Removing the redundant layers of the chassis frees up space for more active material within the same footprint. Structural pack design increases the range of the vehicle by allowing a larger number of cells to be packaged between the wheels. Modules are often discarded entirely in favor of a cell-to-pack arrangement.
This configuration maximizes the amount of energy stored per litre of volume.
Thermal Integration
Cooling plates are frequently built directly into the floor of the housing to save space and weight. The structural pack design must manage the heat generated during fast charging while maintaining its mechanical integrity. If the structure warps due to temperature changes it could affect the alignment of the whole car.