Comparative structural, thermal, and fatigue analysis of connecting rod materials for ural-4320 military diesel engines using finite element method.

Abstract

The connecting rod is a critical component in internal combustion engines, converting reciprocating piston motion into crankshaft rotation. In heavy-duty applications, such as the Ural-4320 military truck, the rod endures high cyclic loads, elevated temperatures, and fatigue stresses, making material selection vital for optimal performance and durability. This study evaluates four candidate materials forged steel (42CrMo4), aluminium metal matrix composite (Al-SiC), titanium metal matrix composite (Ti-6Al-4 V + SiC), and hybrid metal-CFRP composite using finite element analysis (FEA) in ANSYS Workbench 19.2. Structural parameters such as von Mises stress, total and directional deformation, elastic strain, and biaxiality, alongside thermal flux and fatigue life, were examined. Results indicate that titanium MMC offers superior specific strength, thermal stability, and fatigue resistance, while hybrid CFRP achieves significant weight reduction but suffers from limited heat dissipation. Forged steel demonstrates excellent durability and damage tolerance but is penalized by higher density and inertia loads. Aluminium MMC shows competitive thermal conductivity but lower stiffness and fatigue life. Among the evaluated materials, titanium MMC and hybrid metal-CFRP composites provide the best balance between lightweight performance, strength, and fatigue life, making them promising alternatives for future military-grade applications.This study provides a novel, directly comparative multi-criteria assessment of advanced MMCs and a hybrid composite against traditional steel for a specific military application, highlighting the critical trade-offs between specific strength, thermal management, and fatigue life that are often overlooked in singular-focused studies.