Analytical, numerical and experimental investigations on flexural strengthening for wood/PVC composite members using flat bar strips

Abstract

This paper investigates the flexural performances of strengthened wood/PVC (WPVC) composite members using a high carbon steel (HCS) flat bar strip adhered to the tension side and a carbon steel (CS) flat bar strip attached to the compression side. The analytical models, numerical results of finite element analysis (FEA), and experimental investigation are studied. The stress–strain relationship to represent material models for WPVC, HCS and CS were determined. These material models were applied for analytical solution development and numerical model using FEA program of ABAQUS. Good correlations of analytical, numerical and experimental results were obtained for the members before and after strengthening. The deviations of load at specified displacement of the members before and after strengthening on tension side were in average of 5.6% while the deviations of members strengthening on both tension and compression sides were in average of 5.5%. The ultimate loads increased about 1.93 and 1.64 times for edge-wise and flat-wise loading directions, respectively. For the members strengthening on both the tension and compression sides, numerical and experimental results showed a good correlation while analytical models gave an underestimation. The strengthening of members on both sides can improve significantly the bending stiffness up to 4.53–6.00 times, but the ultimate load increased only in the range of 1.45–2.16 times for the edge-wise and 1.78–1.91 times for the flat-wise loading direction due to debonding effects. The use of analytical models and ABAQUS showed good potential for predicting the flexural behavior of WPVC composite members.