An experimental and numerical study on the mechanical behavior of Kunststof Lankhorst Product (KLP) sleepers

This paper studies the mechanical behavior of two types of KLP sleeper, namely low-density polyethylene sleeper (LDPE-16) and high-density polyethylene sleeper (HDPE-25) with 16 mm and 25 mm steel bars diameter, respectively, in static, dynamic and longtime static three points bending moment tests. Therefore, HDPE-25 and LDPE-16 with six strain gauges mounted on their steel bars, were manufactured to assess their mechanical responses. Moreover, a finite element method (FEM) model is developed to perform a sensitivity analysis based on different diameters of steel bars for HDPE with 16 mm (HDPE-16) and LDPE with 25 mm (LDPE-25). The results show that steel bars of LDPE-16 yielded under 4 hours of 30 kN load, while, HDPE-25 shows significant resistance. Numerical results show that HDPE-25 is overdesigned and can be replaced by LDPE-25 which has lower weight and price. The natural frequencies of HDPE-25 are almost 16%, 19%, 16% and 33% higher than the three first bending frequencies and first torsion frequency of LDPE-25, respectively, that proves the better performance of LDPE-25 in case of preventing resonance. Moreover, the bending modulus HDPE-25 is almost 42%, 45% and 65% is higher than HDPE-16, LDPE-25 and LDPE-16, respectively.