Topic: Residual Stress Analysis on Mechanical Components
Time: At 15:00, July 20 (Friday), 2018.
Venue: Room 301, Teaching Building of the School of Mechanical Engineering, East Campus
Lecturer: Vincent JI (Ji Ning)
Vincent JI is a tenure special professor and doctoral supervisor at the 11th University of Paris, France. He is the current Director of the Surface and Coatings Research Office. He has been engaged in the research of the relationship between the microstructure and mechanical properties of crystalline materials, engineering material failure analysis, engineering material residual stress analysis, and development & application of diffraction stress analysis technology. He has hosted and participated in many scientific research projects of the European Union, French Research Department and the French National Scientific Research Center (CNRS).
In the world, he is the first one who proposed the idea of the in-situ (in-situ) X-ray material surface mechanical properties test, X-ray small-angle diffraction measurement stress gradient and non-cube single crystal stress measurement method. He developed the systematic studies in the research of the surface residual stress distribution of engineering materials, the relationship between loading stress and the constitutive relationship of the material surface and the microstructure of the material, which has been widely cited internationally. His more than 110 papers have been published in international academic journals indexed by SCI. He has close contact with European industrial and mining enterprises, long-term cooperation with many European energy, machinery manufacturing, and aerospace companies in civil and defense. He is technical consultant of the SAFRAN-SNECMA Aero Engine Group, AREVE-FRAMATOME Nuclear Power Group and French Nuclear Research Center (CEA). He is an internationally renowned expert.
Residual stress (RS) can be generated dues to material’s fabrication, forming, machining and during component’s utilisation. RS can influence material utilisation properties and their durability. It is important to determine the level and the distribution of RS on mechanical components. The origins of RS generation (mechanical deformation, thermal gradient, microstructure change) will be presented as a function of different process. The influences of RS on material’s properties will be discussed. Different experimental methods, such as hole drilling, layer remove, section method, contour method, diffraction method (XRD, synchrotron, Neutron), ultrasonic and magnetic method, for RS determination will be introduced. The advantages and disadvantages of each method will be discussed. The mechanism of RS control, relaxation and modification will be indicated. Some industrial applications and cases studies of RS control and expertise will be presented.
School of Mechanical Engineering
July 10, 2018