Effects of Temperature on the Evolution of Yield Surface and Stress Asymmetry in A356–T7 Cast Aluminium Alloy
Journal article, 2021

As the electrification of vehicle powertrains takes prominence to meet stringent emission norms, parts of internal combustion engines like cylinder heads are subjected to an increased number of thermal load cycles. The cost-effective design of such structures subjected to cyclic thermo-mechanical loads relies on the development of accurate material models capable of describing the continuum deformation behaviour of the material. This study investigates the effect of temperature on the evolution of flow stress under cyclic loading in A356-T7 + 0.5% Cu cast aluminium alloy commonly used in modern internal combustion engine cylinder heads. The material exhibits peak stress and flow stress asymmetry with the stress response and flow stress of the material under compressive loading higher than under tension. This peak and flow stress asymmetry decrease with an increase in temperature. To compare this stress asymmetry against conventional steel, cyclic strain-controlled fatigue tests are run on fully pearlitic R260 railway steel material. To study the effect of mean strain on the cyclic mean stress evolution and fatigue behaviour of the alloy, tests with tensile and compressive mean strains of +0.2% and −0.2% are compared against fully reversed (Rε = −1) strain-controlled tests. The material exhibits greater stress asymmetry between the peak tensile and peak compressive stresses for the strain-controlled tests with a compressive mean strain than the tests with an identical magnitude tensile mean strain. The material exhibits mean stress relaxation at all temperatures. Reduced durability of the material is observed for the tests with tensile mean strains at lower test temperatures of up to 150 °C. The tensile mean strains at elevated temperatures do not exhibit such a detrimental effect on the endurance limit of the material.


stress asymmetry



mechanical behaviour

isotropic hardening


Elanghovan Natesan

Chalmers, Industrial and Materials Science, Materials and manufacture

Johan Ahlström

Chalmers, Industrial and Materials Science, Engineering Materials

Stefan Eriksson

Volvo Cars

Christer Persson

Chalmers, Industrial and Materials Science, Engineering Materials


19961944 (eISSN)

Vol. 14 24 7898

Development of analysis models for thermomechanical fatigue

Swedish Energy Agency (37807-1), 2013-10-01 -- 2018-12-31.

Driving Forces

Sustainable development

Areas of Advance


Materials Science

Subject Categories

Applied Mechanics

Metallurgy and Metallic Materials


Chalmers Materials Analysis Laboratory



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