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The objective of this study was to provide a normative database of dynamic upper-extremity (shoulder and elbow) joint strengths to fill the current void in literature for multidimensional strength capacity profiles. The isokinetic strength of the elbow and shoulder joints was tested for twenty normal males and females. The independent variables consisted of joint angular position, joint angular velocity, direction of exertion, and gender. The measured joint strength (torque, Nm) was the only defined dependent variable. The majority of existing joint strength prediction models and normative databases are static (isometric) in nature. The few available dynamic models are reported in the form of torque as a function of joint angle. Since joint strength is a function of both the joint angular position and angular velocity, descriptive models should take this interaction into consideration. The dynamic joint strengths of the subjects were studied using the KIN_COM 125E Plus. A second-order multiple regression analysis was used to model the dynamic 3-D strength surface response of each joint in each direction of exertion. Analysis of variance (ANOVA) with repeated measures design was used to test for the effects of gender, angular position, angular velocity, and direction on the dynamic strength of each joint, joint strength was significantly influenced by dynamic parameters such as the angular velocity. The interaction between angular position and velocity was highly significant. 3-D strength surface representation may be used as a "performance capacity envelope" to comprehensively characterize an individual's dynamic joint strength performance.

In this paper, a series of impact tests to advanced high strength steel (AHSS) were carried out through the special equipment. Base on test results, the effects of some key factors such as welding parameters, loading conditions, material properties and specimen structure, etc to the dynamic mechanics property of spot welds were discussed which may be helpful to the actual automobile design and manufacture areas.

Through the dynamic triaxial tests of the tailings material taken from a copper mine, dynamic strength and residual deformation are studied. It is indicated that: the dynamic strength will increase with confining pressure and consolidation stress ratio. The related curves of dynamic shear stress ratio and vibration times have good normalization under different confining pressure. Whether isotropic or anisotropic consolidation, residual axial strain increase with confinng pressure, and the increasing trend are particularly obvious under anisotropic consolidation. The curve of residual axial strain and dynamic shear stress ratio is linear in the log-log coordinate, and the relation can be expressed by a power function.