Nonlinear structural response to combines live load processes

Reliability of structural members with nonlinear material property subjected to combined live load processes is studied. An earlier study using an envelope process yields very wide bounds of values for the first moment of load exceedances (number of loads exceeding apredetermined threshold deformation, Δ₀) and damage duration (total time a process has deformation larger than Δ₀). By assuming that only the sustained load causes permanent deformation, and by modifying the concepts used in a prior study for a contiguous rectangular pulse, are finement on the bounds of the expected number of combined load exceedances and damage duration are found. In addition, the relationship between linear and nonlinear structural response is examined for different elastic limits both in load exceedances and in damage duration.