An elastic,plastic theory of longitudinal growth stresses

Summary The problem of predicting the distribution of longitudinal growth stresses in a symmetrical, standing, woody stem is treated. It is assumed that coupling effects between longitudinal and transverse stress components are negligible so that the longitudinal stress distribution can be determined independently. One novel feature introduced in this analysis is that the material behaviour is assummed to be elastic, plastic rather than wholly elastic as in previous analyses of this problem. This assumption successfully limits the maximum intensity of the longitudinal compressive stress near the center of the stem. Another novel feature of the present analysis is that the initial, longitudinal, tensile stress at the periphery of the stem varies inversely with the size of the stem rather than being assumed constant as in previous analyses. Results obtained from this analysis are compared with previously published experimental data for curvatures and length changes of strips cut from diametral planks. The agreement is very good with the length change data over a wide range of stem sizes.