By testing， analyzing and comparing, the demands on high temperature and high stability for piezoelectric elements are proposed, and it is confided that Bi-Ti series crystal is the suitable piezoelectric material in making accelerometer transducer.
Based on the analysis of heat transfer route and heat transfer mode on frame tooling，and the analysis of air flow pattern in autoclave process，emperature field distribution is researched from simulative to practical experimen.
A low power YAG pulse laser-TIG arc hybrid thermal source welding system is established, in which stainless steel 1Cr18Ni9Ti is welded and weld enetration of stainless steel under 3 kinds of thermal sources is studied. The effect mechanism of hybrid thermal sources on welding penetration is analyzed by introducing the concept of effective thermal input of welding.
This paper briefly introduces the development tendency of transparency technology and materials of aircraft. The forming methods of organic transparency are summarized, and the research of a complex shape transparency formation for an aircraft is described.
By using the finite element met-hod, the simulation analysis and test verification on the tubes’ cross￣section deformation are carried out. It is pointed out that the change of tubes’ larger cross-section occurs nearby bending center corner and the change of smaller one takes place in tubes’ tangent segment. After the finite element calculation, there is large deviation in change-ratio of long axis on the cross-section, actual the reason is caused by the error of the match between tubes and dies.
Numerical analysis and theory analysis are presented to research the stress and strain of rivet during squeeze riveting. The whole process is divided into five stages, and the metal flow and force squeeze status are analyzed in every stage. Using ANSYS/LS-DYNA, the squeeze riveting process is simulated, and the strain and stress distribution and the variation law on the rivet and workpiece are given.
