Viscoelastic Framework
Mathematical representations of mechanical behavior combine springs and dashpots to simulate how paperboard reacts to load over time. The alfrey burgers model specifically provides a four element configuration to calculate the combined effects of instantaneous elasticity and delayed deformation. It accounts for the way a corrugated box initially resists a stack but slowly yields as fibers slide and adjust.
Temporal Response
Creep deformation occurs when a material undergoes permanent change while held under a steady weight that remains below its breaking point. By using the alfrey burgers model, engineers separate the initial elastic recovery from the irrecoverable viscous flow that leads to carton failure. This distinction allows for the calculation of how long a secondary packaging unit survives in a warehouse before the side walls buckle under the weight of the pallet above.
Accurate prediction requires laboratory data on the specific liner and medium combination to set the constants for the dashpot elements.
Measurement Boundary
The validity of the calculation depends on maintaining loads within the linear viscoelastic range. When the stress applied to the board exceeds a certain percentage of its ultimate strength, the alfrey burgers model ceases to accurately track the accelerated damage. High humidity environments also alter the material constants and necessitate a correction for moisture induced acceleration.
