Structural Analysis of a Pultruded Composite Beam: Shear Stiffness Determination and Strength and Fatigue Life Predictions

摘要: This dissertation is focused on understanding the performance of a particular fiberreinforced polymeric composite structural beam, 91.4 cm (36 inch) deep pultruded double-web beam (DWB) designed for bridge construction. Part 1 focuses calculating Timoshenko shear stiffness DWB and what factors may introduce error in experimental measurement quantity this other sections. Laminated theory finite element analysis (FEA) were used to estimate stiffness. Several references literature have hypothesized an increase effective measured due warping. A third order laminated (TLBT) was derived explore concept, warping effect found be negligible. Furthermore, FEA results actually indicate decrease at shorter spans simple boundary conditions. attributed transverse compression load points supports. The higher sandwich Frostig shows promise estimating related thin-walled beams. 2 attempts identify failure mechanism(s) under quasi-static loading develop strength prediction DWB. utilized investigate two possible modes top flange: carbon fiber plies delamination free edges or taper regions. onset predicted using strength-based approach, stress accomplished successive sub-modeling approach ANSYS. analyses inconclusive, but strengths based mode show excellent agreement with data. fatigue life prediction, assuming failure, also developed remaining critical concepts Reifsnider et al. One fatigued about 30% ultimate capacity showed no signs damage after 4.9 million cycles, although number cycles 4.4 million. test second 60% incomplete time publication. Thus, success not confirmed.