Coupled Thermal-Structural Loading and Performance Analysis of a Connecting Rod in a Diesel Engine

Abstract

The purpose of this research is to evaluate the coupled thermal
structural response of a diesel engine connecting rod and to
identify the most efficient material capable of maintaining
structural integrity under realistic operating temperatures and
mechanical loads. A coupled thermal structural finite element
analysis was conducted using ANSYS 2024 R1, in which a
three-dimensional connecting rod model was subjected to
combustion-induced thermal loads and mechanical loads arising
from gas pressure and inertia forces. Three aluminum-based
materials AA356.0-T6,
Al7039/Cu/SiC
metal matrix
composite, and Al7050-T7451 were investigated to assess
their thermo-mechanical performances. The result indicates that
AA356.0-T6 and Al7039/Cu/SiC experienced excessive
thermal deformations of 27.719 mm and 29.778 mm,
respectively, with equivalent stresses exceeding 11,000 MPa,
reflecting poor stability under coupled loading. In contrast,
Al7050-T7451 exhibited significantly lower deformation of
2.9211 mm and a maximum stress of 502.62 MPa. The major
findings demonstrate that Al7050-T7451 possesses superior
resistance to thermal expansion and stress concentration
compared with the other materials evaluated. The major
conclusion drawn from this study is that Al7050-T7451 is the
most suitable material for diesel engine connecting rod
applications, offering enhanced thermo-mechanical stability,
improved reliability, and reduced risk of failure under elevated
temperature and pressure conditions.