Temperature And Media Impact On The Fatigue Performance Of Tailor-welded Blank

Welding is a mature, promising technology. Welding has a broad and in-depthapplication in many fields, like machinery manufacturing, automotive, shipbuilding,marine engineering, aerospace engineering. The medium and temperature thatproducts be in have certain effect on the fatigue life, need further research In thisartical, fatigue test of the Laser Tailor-welded Blank were carried out in water and airmedium and at different water temperature.The main include the following:First, a liquid circulation based on thermostatc appliance were designed andmanufactured, which provide a equipment for study fatigure life in different mediumand temperatures. It composes of retaining portion，the liquied cycle portion and atemperature control section. Application results shows that the temperature can becontrolled at set temperature, the difference is in±1°C. It can work steady in fatiguretest.Then, fatigue test of the Laser Tailor-welded Blank were carried out in water andair medium and at different water temperature. The experiment is divided into fourgroups:20°C air,20°C water,40°C water and60°C water Experimental resultsshowed the break positions are focused on the welded joint. Water have a significantimpact on the metal fatigue properties of welded joints, and will greatly reduce thefatigue life of welded parts. The fatigue performance will be reduced as thetemperature rises, but this effect is much smaller than the water. In all, the water andthe temperature have a combined effect on fatigue life of welded joint and the effectwas not a simple superposition, but a mutually reinforcing effect.Finally, the welded joint models influence on the fatigue prediction is studied.Welded joint is processed into different models, including the conode, the rigid, beam,solid connection. Studies showed the predicted fatigue life are same by the conode,rigid element, solid connection, but less by bean element.The test setup build in this research can be used to study materials fatigure life indifferent medium and temperature, which is meaningful to prodict structural design.