外文翻译---大型轴承螺栓接头数值模式的发展(编辑修改稿)

外文翻译---大型轴承螺栓接头数值模式的发展(编辑修改稿)内容摘要：

tor and the way themember stiffness is distributed. Zhang [10] developed a new analyticmodel of bolted joints and takes into consideration the stiffness reduction associated with the residual force on the assembly, pression deformation caused by external force and dimensions changing due to member rotation. This model has its limitation and is not applicable to bolted assemblies when the members are of different geometry or when the external forces are not symmetric about the member interface. The specificmodel we are proposing for large bearings can serve as base for a genericmodel of circular flanges which can take into account the different nonlinearities as well as different configurations or geometries by appropriate stiffness distribution. 2. The slewing bearings The model this article proposes is suitable for specific bolted joints for large diameter bearings. These large bearings (up to 13m(43 ft)) also called ―slewing bearings‖, are used for cranes, radar dishes, tunnelboring machines, etc. The two bearing rings are clamped to the main frame by preloaded high strength bolts. One or both rings are provided with gear teeth to enable the swing drive to operate. The connection is like a thick and narrow cylindrical flange on a very rigid frame fastened with a large number of bolts. Another particularity of the system is the important and variable overturning moment. The bearings are subjected to radial and axial loads of same importance. The three types of bearings under study, ball bearings, crossedroller bearings and threerow roller bearings, are presented in Fig. 1. Due to the plexity of structure and the particularity of bolted joint loading, neither traditional models nor nonlinear models are appropriate. Thus we have developed a new model that takes into account simultaneously the bending stiffness in the axial direction with shell elements and in radial direction with tubelike elements. Furthermore, the tube elements were modified to consider the characteristics related to the behaviour of preloaded bolted assemblies. Therefore, the modelling process lies in the definition of an original ―hybrid‖ finite element has the general behaviour of a ring except for the axial direction where its stiffness is related to the local stiffness that governs the behaviour of the bolted assembly. Meshing the ring with several elements allows taking into account nonlinear stiffness distribution in the assembly and in particular the effect of the load application height. The evolving contact area is modelled by contact springs and using an iterative solving technique. Fig. 1. Slewing bearings. 3. Modelling and assumptions The specific loading on these systems is an offcentre axial load (a normal crane loading type) resulting in a large overturning moment. This will build up an internal load on the bearings grooves (as shown in Fig. 1). At this stage of development, the intensity of the external load is not important. It is sufficient to apply the same loading on both models: the 2D numerical model and the 3D finite elements model used to tune the first one up. To build the numerical model, several simplifications were made: • for modelling purposes, we consider only the most loaded bolt and the associated sector。 • the outer ring only is modelled. Thus the external forces are replaced by the rolling elements load as an equivalent load which increase the working load on bolts。 • the loading as well the formulation of the specific elements are considered axisymmetric。 • the mounting is considered extremely rigid. Fig. 2 presents the principle underlying the new modelling. On the lefthand side is the sketch of the numerical model and on the righthand side is the equivale。