Economic efficiency of glued joints in timber truss systems

The potential losses associated with glue as a jointing material in timber construction is examined when inherent uncertainties in the basic design variables are quantitatively appraised. The Mean First-Order Second Moment Method (MFOSMM) and Value Analysis (VA) are developed to estimate the reliability indices and the associated risk costs of the joints of an example roof truss. The variables which describe the loading, grade stress and geometrical properties applicable to joint analysis are treated as random variables and they are assumed to be normally distributed. The results show indicative trends of the dependence of joint reliability and cost of failure loss on the degree of workmanship.