Effect of Temperature on Static and Impact Properties of New Softwood Pallets

Abstract

The first part of this study verifies that static compressive strength of new wooden pallets decreases as temperature increases. The drop of compressive strength is at a small rate of 0.61 psi per 1°F of temperature increase within the temperature range of 80°F to 160°F. This is consistent with the current timber structural design practice. The strength reduction is small and has little effect on pallet static compression performance. The second part of this study investigates impact acceleration from free-fall drop tests performed at temperatures ranging from 80°F to 160°F. As temperature rises, specimens become weaker thus they absorb more impact energy, which results in lower impact acceleration. The drop of impact acceleration is also at a small rate of 0.034g per 1°F of temperature increase. When temperature rises from normal temperature of around 80°F to a high temperature of 160°F, the impact acceleration reduces about 2.72g. This rise results in less potential damages on products on the pallet. The third part of this study looks at the impact acceleration due to horizontal impact due to a forklift at a lower range of temperature of 33°F to 72°F. The drop of impact acceleration is at a faster rate of 0.674g per 1°F of temperature increase. When temperature drops from 59°F to 48°F, the impact acceleration increases about 7.41g. This increases the damage potential of products on pallets.