Direct Boundary Element Method Analytical Research On The Beam And Its Joints

The virtual prototyping technique is a kind of developing techniques with new mode for the development of new products, which has important meanings towards raising the product quantity, lowering the developing cost and shortening the trial-manufacturing period. And the whole machine characteristics of mechanical system (including the state of static, dynamic and hot) is a key index that affects the whole machine quantity. Therefore, the mechanical characteristics of whole machine must be estimated and analyzed on the condition of satisfying the function requirements during the system design stage. In general, it is difficult to solve the flexible joints by the FEM for a large amount of parts and flexible joints are included in the mechanical system, especially when solve the flexible joints under complex joint states using the iterative method. But it is convenient to solve flexible joints in mechanical systems by BEM. The BEM can put the flexible joints into the boundary models of the whole machine characteristics directly in a component style or a joint condition style. Thus, it is meaningful to model and analyze the mechanical system parts, assembly and the whole machine by BEM.This paper mainly researches the DBEM (Direct Boundary Element Method) modeling and analyzing for the static and dynamic characteristics of the beams and its joints. The static characteristic DBEM (Direct Boundary Element Method) analytical formula of the beam with internal boundary and the beam on the elastic foundation problems are deduced. The static and dynamic characteristic DBEM (Direct Boundary Element Method) analytical formula of beams under the state of pull and press, torsion and bending problems is deduced. And the DBEM (Direct Boundary Element Method) analytical formula of the components jointing in rigid and flexible problem is deduced. Then corresponding analytical software is developed based on the MATLAB language according to the DBEM (Direct Boundary Element Method) formulas deduced and the calculating example testifies its accuracy.