The Tensile Strength of Redwood Perpendicular to the Grain and its Dependence on Moisture Content and Temperature,

摘要

The cracks which can occur in timber during drying,due to the stresses caused by shrinkage,are initiated when the stresses exceed the ultimate strength. It is therefore important to know whether the ultimate strength changes during the drying process in such a way that,for instance,more sensitive intervals are passed. The tangential strength which is the most critical steadily increases as the moisture content drops,while the radial strength is more irregular. The spread is larger at low values of the moisture content in the case of the tangential strength,due to the presence of internal stresses,while the spread in the radial direction is large over the whole range,since the properties of the individual annual rings exert a greater influence in this case.