Modal Analysis Of Heald Frame Of Air-jet Looms

The research object of the thesis is the modal characteristics of heald frame of air-jet loom. Heald frame is the key device of warp's heddle motion. It requires the heald frame has good dynamic performance to make the weaving process goes smoothly. The research work of the subject mainly use the finite element method (include using the software ANSYS and programming with Matlab depending on the finite element theory) and vibration experiment theory (vibration analysis software DASP2003 and corresponding hardware equipment ).The thesis do analysis work of the frame's dynamic properties from calculation,and experiment aspects,and explore the calculation method of the plastic vibration reduction part.At first chapter of the thesis the frame's working characteristics and present situation of modal anslysis are introduced.At the second chapter of the thesis the frame's modal properties are caculated by the finite element analysis software ANSYS,the modal informations of the frame is obtained.It discovered that the low order mode which has great influence on the frame's perfoemance are mianly transverse vibration though the mode analysis of the frame.There are some treatment at the process of the establishment of the frame's finite element model,some details which don't effect the result are simplified,do linear treatment with the nonlinear vibration of the plastic vibration absortion parts.The third chapter of the thesis connect the work above,do experiment with real heald frame and collect the experimental informations of the frame.Comparing the calculation result with the experimental one, and modifying calculation model,do the dynamic modification work by changing the mass and stiffness of the frame in order to improve the frame's dynamic property,the result showed that the changing of the cross section shape has graet effect on the frame's dynamic property.At the fourth part of the thesis calculation are carried out with the dynamic substructure method.Treating the plastic vibration absortion parts as link substructure do modal synthesis,the result is basic coincidence with the experiment.The feasibility of the calculation method is testified.At the last part of the thesis some summaries are given to the whole thesis.Some ideas to improve the work furtherly are put forward.