The forging method with horizontal V-shaped anvils (HVA) is effective in the control of inner stress states, metal tissue, etc. FEM numerical simulation is conducted for the HVA forging method, under various processing parameters. The results show that during HVA forging, the transversal and axial stress states in the middle part of forgings are influenced by not only the ratio of the anvil width to billet height (anvil-width ratio )but also the ratio of the blank width to billet height (blank-width ratio) and the reduction ratio, while the end parts are influenced little. Among those processing parameters, the reduction ratio plays an important role. When the reduction ratio is 5% or 10%, it is possible to obtain axial and transversal tensile stress. When the reduction ratio is larger than 15%, it is easy to obtain two-way compressive stress. Therefore, in order to control the two-way tensile stress, big reduction ratio should be adopted. Small blank-width ratios result in the forgings cracks because of transversal tensile stress in common flat-anvil stretching method. On the contrary, even if the blank-width ratio is small, transversal compressive stress can be generated in forgings for the HVA forging method, only if the matching of the anvil-width ratio and the reduction ratio is suitable. The feature of the HVA forging method benefits the preventing forgings from inner cracks. The results provide the theoretical foundation for the application of the HVA forging method.
Introduction: Rhythmic gymnastics uses the body as a tool for expression and choreographed beauty. Athletes use various body movements and beautiful voices to create a competitive sport that combines technology and art. This high-level sports performance set results from much targeted fitness training. Yet, the sport lacks research relating fitness to the difficulties of the new rules. Objective: This paper explores the choreographic differences in rhythmic gymnastics under the current rules. The differences in athletes’ body fitness are also evaluated. Methods: The fitness indices of 120 rhythmic gymnasts were evaluated by a developed method encompassing the upper body, trunk and lower limbs. A general analysis of the movement organization characteristics of Chinese rhythmic gymnasts was also performed. Armed with these data, the mathematical statistics method was adopted to conduct empirical research. results: The 10-second long jump, standing jump, lifting, plank, and other 10-s performances in elite athletes were significantly more expressive than those in ordinary athletes (P<0.01). In the lifting test, elite athletes were significantly better than ordinary athletes (P<0.01). There was a significant difference between elite and ordinary athletes in the plank stand (P<0.05). There was no significant difference in the remaining individual scores. Conclusion: The critical period of the upper limb development of rhythmic gymnasts is significantly lagged compared to the lower limbs. The artistic arrangement of rhythmic gymnastics is fundamental to its good presentation. The innovations and diversified changes evidenced an advance in rhythmic gymnastics that athletes must absorb to achieve better competitive results. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.