Based on elasticity plate theory and earlier models of mat formation (MatForm), pressing (MatPress), and OSB properties (OSB-Pro), a comprehensive computer model (OSB-CSL) was developed to simulate the spatial distribution of deflections and stesses as well as ultimate load (UL) of OSB panels under CSL loading. Laboratory tests were conducted to validate the model. This model simulates the stochastic variation of ULs due to heterogeneous mat formation and localized strength properties. The following conclusions can be drawn:
1) CSL loading in OSB typically goes through four stages: linear elastic deformation, yielding due to initiation of localized debonding, ductile deformation due to multiple debonding and crack propagation, and catastrophic failure in the form of punch shear failure.
2) CSL performance is highly dependent upon the uniformity of mat formation and the consistency of board properties, particularly bending MORs. Due to the inherent forming variations, a certain percentage of samples will be deemed to fail, which often makes it difficult to meet the current performance standard.
3) Smaller loading heads result in lower loading capacity due to stress concentration.
4) Localized MOR has a direct impact on UL. Variability in MOR from quality control tests can be used as a predictor for CSL performance.
5) Strand orientation has a strong impact on bending and CSL properties. Improving orientation in both face and core layers can lead to increases in ULs.
6) CSL properties can be improved by: using longer and thinner strands, increasing resin content (mainly for increasing UL), reducing fines content and increasing panel density.