Four finite element models of a slewing bearing with different supporting structures are established by the finite element software ANSYS. In these models, the ball–race contact is simplified by the spring element with the same contact stiffness. The nut and bolt head are simplified and coupled with the surface of other connected component. The preload is applied on the bolt by a few pretension elements. The ball–race contact forces, fatigue lives, and carrying capacities of the slewing bearing in the four models are calculated. The effects of supporting stiffness, bolt number, and bolt preload on the contact force and fatigue life of the slewing bearing are studied. Moreover, the effects of supporting stiffness, bolt number, bolt preload, ball–race contact truncation, and bolt–hole backlash on the carrying capacities of the slewing bearing are analyzed. Results show that the fatigue life and carrying capacity of the slewing bearing can be enhanced by appropriately decreasing the supporting stiffness. Optimal values of bolt preload and number for the fatigue life and carrying capacity of a specific slewing bearing are obtained.

High-K calc-alkaline granitoids play a key role in understanding the formation and evolution of the continental crust. Herein, we present new laser ablation inductively coupled plasma mass spectrometry zircon U-Pb and Lu-Hf isotopic, whole-rock geochemical and Sr-Nd isotopic data of early Jurassic high-K calc-alkaline granitoids in the Zhanggunagcai Range, NE China. In situ zircon U-Pb dating shows that the granodiorite-monzogranite-granite (GMG) suite was emplaced at ca. 192-187 Ma. They are high-K calc-alkaline and weakly peraluminous, similar to the geochemical characteristics of I-type granites. The GMG suite has lower bulk-rock initial 87 Sr/ 86 Sr ratios of 0.7037-0.7042, slightly positive ε Nd (t) values of +1.10 to +1.87 and highly positive zircon ε Hf (t) values of +5.3 to +10.9. This result suggests a major contribution of juvenile crust to the magma source. The tetrad rare earth element patterns and highly negative Eu anomalies of samples with high SiO 2 contents indicate that fractional crystallization plays an important role in the genesis. Together with data in the literature, we infer that the early Jurassic granitic rocks have been formed by partial melting of juvenile arc crust associated with the westward subduction of the Paleo-Pacific Plate.