deletions | additions       diff --git a/method.tex b/method.tex  index b6e26f2..735b004 100644  --- a/method.tex  +++ b/method.tex 
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Where S is the stocking rate, assumed to be either open grown, one stem per hectare or 741 stems per hectare.  As trees grow, the newest cells are superimposed on the existing structure, creating a time evolving stress state. In order to acomidate these time dependent changes, the mesh needs to be 'grown', here time is treated in descrete steps. Wind effects are not acounted for during growth, however, self weight and growth stress are. Gravity is the only external force considered during the growth phase, as the tree grows it compresses under self weight, resulting in the lower parts of the stem becoming successively compressed by the new growth. Growth stresses develop as cells divide in the cambium, resulting in the new cells being in a non-stressed state on the surface of a pre-stressed structure. During secondary wall formation there is a tendency for cells to contract longatudinly, for more details see ---refs---. As the pre-existing strucute restrains further contraction a stress profile of longitudinal compression at the centre of the stem and tension at the outer edge.