Abstract:Under 3-point sustained, un-symmetrical cyclic loading at constant temperature (18℃) and humidity (45—65% rh) condition but at various stress level from 20% to 100%, a group of experiments has been carried out on the creep behavior of birch laminated boards (LB) with 3 types of distinct assembly, which are employed in gymnastic vaulting-board. Results show that dynamic creep curves of LB are much analogous to those of many wood materials under static load. Using an iterative least squares computer program written by ourselves, the dynamic creep curves based on 3-and 4-element rheological model have been fitted to the 17 sets of data from specimens. Until 105 cyclings, the 4-element model always provides the better overall fit to the data, for which the multiple correlation R2 is more than 0.99 at each condition. The 3-element model seems appliable within the duration of delayed elastic stage, i.e. the primary creep region, in general.