Respon Polymeric Foam Yang Diperkuat Serat Tandan Kosong Kelapa Sawit (TKKS) Akibat Beban Tekan Statik Dan Impak (Simulasi Numerik)

Abstract

Experimental and numerical work was reported on the problem of the response of oil palm empty fruit bunch (OPEFB) fiber reinforced polymeric foam under static and impact loading conditions. In the experimental investigation, the static axial compressive test was applied on polyurethane, thermosetting resins, and OPEFB fiber reinforced polymeric foam specimens and these specimens were conducted on a servohydraulic material testing machine. The averaged stress-strain response and the fracture modes in each type of materials were derived from static test. The fracture modes in each type of materials and the collapsed cells of OPEFB fiber reinforced polymeric foam were observed by a scanning electron microscope. In the numerical simulation, the variation of the distributions of normal stresses with normalized time in OPEFB fiber reinforced polymeric foam due to static and impact wave propagation was analyzed by using a finite element method (FEM). The finite element code ANSYS and NASTRAN were used for numerical stress analysis. The obtained summaries were as followed: (1) The yield stress, the maximum stress, and the strain to failure were influenced by foams, these foams reduced the stress and decreased the strain to failure. The fracture modes were also found to be considerably different for each type of materials. Polyurethane exhibited random macroscopic fracture, thermosetting resins and OPEFB fiber reinforced polymeric foam exhibited shear dominated failure and the cells suffered progressive crushing. (2) Based on FEM computation results were found that the fracture mechanism corresponded to the regions of the static compressive stress concentration. (3) FEM computation results suggested that the propagation of incident compressive stress wave related to impact loading. (4) Based on the static axial compressive test results, the Young’s modulus and the stiffness were determined and it was found that thermosetting resins may also contributed to increased the stiffness of polyurethane.