Syudy On The Parametric Modeling System Design And Finite Element Analysis Of The Crankshaft Based On Ug/Ansys

The crankshaft is one of the most important parts of internal combustion engines, and a part bearing complicated loads. So, it’s very essential to study the strength of the crankshaft during the engine design process. With the development of world science and technology, the technical requirements of the crankshaft will be increased. The paper aims to establish a crankshaft parametric3D modeling system, and to complete the finite element analysis of a crankshaft and its strength checking.In this paper, a parametric modeling system for crankshafts of four-stroke internal combustion engines was firstly developed to make an intensive study of parametric design, combining the secondary development technology and the secondary developed tools provided by UG NX6.0with Microsoft Visual C++6.0. Next, a mechanical model of crank mechanisms was established based on the motion analysis of crank mechanisms and the mechanical analysis of crankshafts. Especially, the solution process of the refrigerant pressure and the reciprocating inertia force of the piston assembly were described in detail, respectively based on the indicator diagram of internal combustion engines and the static equivalence principle. Then, according to the traditional theory and the stress distribution law of finite journal bearing, the mathematical model of the pressure distribution of the rod journal was established. Based on the pressure distribution model, the crankshaft of a four-stroke six-cylinder in-line engine was analyzed under six working states, and the pressure distribution function and the corresponding load carrying area of each rod journal were obtained. In the system, the3D model of UG could be well imported into ANSYS without any data loss by seamless connection between UG and ANSYS, which realized the data sharing between CAD and CAE, and made a good preparation for the finite element analysis of the crankshaft. Finite element analysis was performed on the crankshaft of a six-cylinder in-line engine under six working states using ANSYS12.0to find out the the dangerous section of the crankshaft intuitively and easily. Finally, according to the results of finite element analysis, the static strength and the fatigue strength of the crankshaft were checked, and the result shows that the crankshaft meets the strength requirement.