Sensitivity analysis of shear modulus on Lateral – Torsional Buckling of PFRP Beam

Abstract

An elastic constant of Pultruded Fiber Reinforced Polymer (PFRP) has a wide range of value, especially for the shear modulus which is generally ranging from 3 to 5 GPa. Lateral – torsional buckling (LTB) is a type of global buckling occurs when the beam is under bending about its major axis. The instability happens when the beam twists and move laterally. This research analyses and evaluates the sensitivity of changing the shear modulus on the critical LTB load of PFRP beam using a numerical approach by ABAQUS. It is found that the critical LTB load increases 17% for short beam and 27% for long slender beam when shear modulus increases from 3 to 5 GPa. The influence of changing of shear modulus is reduced when load position moves from top to bottom flange. It is suggested that the determination of proper shear modulus (upper and lower bound of values) is of crucial in design and in validating the compatibility between experimental work and numerical or theoretical analysis.