EVALUASI DESAIN PROFIL PENAMPANG MELINTANG TERHADAP KINERJA PERISAI KOLONG BELAKANG PADA TRUK MENGACU STANDAR KESELAMATAN KENDARAAN

Abstract

Rear underrun protection is a passive safety device installed on freight vehicles whose rear ground clearance exceeds 700 mm and whose rearmost axle is located more than 1,000 mm from the vehicle rear end. The geometric disparity between heavy and light vehicles creates a critical safety hazard, wherein the front structure of a light vehicle may underride the chassis of a heavy vehicle during a collision event, thereby significantly increasing the likelihood of severe or fatal injuries. Consequently, the presence and structural performance of rear underrun protection systems constitute a crucial element in mitigating road traffic crash severity. This study aims to assess the structural performance of four alternative rear underrun protection designs with respect to compliance with Indonesian regulatory standards, specifically Ministerial Regulation PM 74/2021 and Indonesian National Standard SNI 7522:2009. The investigated designs employ commonly adopted cross sectional profiles. The methodological framework involves geometric modeling of the underrun protection structures followed by numerical simulation using finite element analysis to characterize stress distribution and deformation behavior under loading conditions. The simulation results indicate that the maximum von Mises stresses in all design variants exceed the material yield strength, with peak stress concentrations occurring at the support members near the vehicle frame connection. The maximum stresses are 12.041 MPa for the channel profile, 5.627 MPa for the square profile, 2.846 MPa for the box profile, and 1.807 MPa for the pipe profile. Maximum displacements are observed at the free end of the transverse beam. Although deformation levels remain within the allowable deflection limit of 400 mm, the resulting deflections vary significantly across designs, namely 245 mm (channel), 119 mm (square), 21.8 mm (box), and 25.9 mm (pipe).