Showing 3 results for Fatigue Life
M. Azadi, M. Baloo, G. H. Farrahi, S. M. Mirsalim,
Volume 3, Issue 1 (3-2013)
Abstract
In the present paper, a complete literatures review of thermal barrier coating applications in diesel engines
is performed to select a proper type and to find coating effects. The coating system has effects on the fuel
consumption, the power and the combustion efficiency, pollution contents and the fatigue lifetime of engine
components. Usually there are several beneficial influences by applying ceramic layers on the combustion
chamber, including the piston, the cylinder head, the cylinder block, intake and exhaust valves by using a
plasma thermal spray method. Several disadvantages such as producing nitrogen oxides also exist when a
coating system is used. In this article, all effects, advantages and disadvantages of thermal barrier coatings
are investigated based on presented articles.
E. Honarvar Gheysari, A. Babakhani, A. Haerian,
Volume 4, Issue 1 (3-2014)
Abstract
Shot peening applies a residual compressive stress field (RCSF) on the surface of parts. It also shifts “crack nucleation sites” to sub-surface locations. A nondestructive method of measuring the stresses, Sin2ψ was utilized here and the stress values introduced to Ansys software. For this purpose, uniform stress in all directions was applied on the con rod. Loading on the rod in Ansys had three steps: RCSF caused by shot peening (measured by XRD), and tensile and compressive stresses caused by inertial and gas forces, respectively (calculated). Fatigue Macro of Ansys was resumed carrying out the cyclic loading and thereby, improvement of powder forged connecting rods' fatigue life, caused by shot peening was obtained.
Hojjat Ashouri,
Volume 12, Issue 4 (12-2022)
Abstract
Due to the complex geometry and thermos-mechanical loading, cylinder heads are the most challenging parts among all parts engines. They must endure cyclic thermal and mechanical loading throughout their lifetime. Cast aluminum alloys are normally quenched after solution treatment process to improve aging responses. Rapid quenching can lead to high residual stress. Residual stress is one of the main reasons for failure of cylinder heads. The effect of residual stress on the thermal stress and low cycle fatigue life (LCF) of cylinder heads was studied. For this goal, Solidworks software was used to model the cylinder heads. Then the thermo-mechanical analysis was performed to determine the temperature and stress field in ANSYS software. Finally, the fatigue life analysis that considers residual stress effect was done. The results of finite element analysis (FEA) proved that the effect of residual stress in LCF is significant which is not negligible. Thus, residual stress must be considered in the thermo-mechanical fatigue analysis of the engines cylinder heads. The numerical results showed that the area where the maximum temperature and stress is occurred is where the least LCF is predicted.
