Module Compression Pad Mechanics under Non Linear Swelling Force Profiles
Non-linear swelling forces mandate hyperelastic compression pads that hold module interfacial pressure between 0.02 MPa and 0.60 MPa over full cell life.
Ogden Material Model
Meaning
Non-linear strain energy functions formulated in terms of principal stretch ratios characterize elastomeric behavior under high compression and complex multi-axial strain field conditions. Engineers utilize the ogden material model to simulate severe mechanical compression and large strain response in structural battery foams and sealing gaskets. The model formulation is bounded to hyperelastic polymeric and rubber-like solids undergoing large elastic deformation and excludes plastic material yield analysis.
Principal Stretch
Direct formulation using stretch ratios enables precise modeling of severe non-linear material behavior without relying on invariant approximations. The ogden material model expresses strain energy as a sum of fractional powers of principal stretch ratios along orthogonal axes. Adjustable power coefficients allow the model to capture upturns in stress-strain curves at high strain levels.
This capability is essential for simulating elastomeric materials compressed beyond fifty percent strain within tight module enclosures.
Curve Fitting
Mechanical test datasets derived from uniaxial and biaxial strain experiments provide the input parameter values needed for mathematical fitting. Calibrating an ogden material model requires optimization algorithms to solve for multiple shear moduli and strain exponent pairs simultaneously. High order formulations with three or more terms closely match experimental curves across wide deformation ranges.
Accurate parameter sets prevent structural simulation software from overestimating or underestimating cushion support forces.
Large Deformation
Extreme mechanical conditions encountered during battery crash impacts or extreme pouch swelling demand robust non-linear constitutive models. Utilizing an ogden material model ensures numerical stability during severe mesh distortion in finite element crash simulations.