Dynamic Strain Rate Modeling for Multi Ply Boxboard under Rapid Compression
Dynamic strain rate modeling predicts multi-ply boxboard Z-direction compression and interlayer shear collapse during high-speed converting and package drops.
Cell Wall Buckling
Structural Failure
Corrugated board boxes undergo severe localized deformation when the vertical flutes lose their load-bearing capacity under high top-to-bottom compression loads. This specific mode of collapse, termed cell wall buckling, occurs when the individual paperboard liners or medium walls bend out of their original flat plane under stress. The failure typically begins at a minor structural defect or moisture-weakened region before spreading across the panel.
Compression Resistance
Structural design of packaging relies on formulas like the McKee equation to predict the peak load a box can withstand before failing. When cell wall buckling occurs, the structural integrity of the entire container is lost instantly because the flutes can no longer support the load. This failure leads to the crushing of the flutes and the subsequent collapse of the stacked cartons.
Moisture Influence
Fiber-based materials weaken as relative humidity rises because water molecules disrupt the hydrogen bonds holding the cellulose chains together. In humid warehouse conditions, the critical stress required to initiate cell wall buckling drops to less than half of its value in dry environments. This sensitivity to moisture means that corrugated boxes must be designed with high safety factors to prevent catastrophic failure during seasonal transport and storage in humid regions.