Fatigue behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP)

Abstract

The static and fatigue bending behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP) has been investigated by four-point bending tests. Fatigue panels and weakened panels (wESCP) with an initial interface defect were manufactured for the fatigue tests. Stress σ vs. number of cycles curves (S-N) were recorded under the different stress levels. The primary failure mode in the fatigue tests was observed in the shear zone (epoxy debonding), which was different from face failure in the pure bending zone for the static bending test. For residual bending (RB) test, epoxy debonding failure occurred between the pure bending zone and shear zone. Macro cracks along the core/face interface developed as the number of cycles increased during the fatigue life. The crack propagation or damage for the panels submitted to fatigue test can be described as a three-stage damage process of first non-linear portion, followed by linear damage accumulation, and lastly nonlinear accelerated damage. Bending stiffness degradation at the higher load level had faster degradation during fatigue life. The dissipated energy of the panels was small due to the high stiffness of the materials.

Static and dynamic tensile shear test of glued lap wooden joint with four different types of adhesives

“…The results showedthe importance of fatigue in wood applications and wood products. The subject is especially important when a high strength per weight ratio is required (Bonfield et al 1992;Bond and Ansell 1998;Jamieson 2011;Li et al 2016). The role of fatigue damage in wood was also studied (Kyanka 1980;Tsai and Ansell 1990;Bonfield and Ansell 1991).…”

Quasi-Static Compression and Low-Velocity Impact Behavior of Tri-Axial Bio-Composite Structural Panels Using a Spherical Head

“…At the USDA, Forest Products Laboratory (FPL), new research is being conducted to develop bio-composite materials to enhance performance for various engineering applications including tactical shelters, packaging, building materials, and air pallets [ 6 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. High stiffness characteristics were the primary consideration for performance.…”

Fatigue behavior of Japanese cypress (Chamaecyparis obtusa) under repeated compression loading tests perpendicular to the grain

“…These authors also proposed a method for estimating fatigue life. Li et al (2016) conducted a bending fatigue test to verify the potential use of an engineered sandwich composite panel that is lightweight and has high strength performance. An improvement of bending fatigue characteristics was suggested based on the observation of failure modes.…”