| With the advancement of science and technology, the wide range of needs of production and life, there has been an increasing number of hand tools. For a long time, people starting research on the shapes of tool handles and the handle-grasp from the ergonomic. The evaluation of hand tools has already begun. The distribution position and the sizes of hand surface pressure are important indicators to evaluate the comfort of grasp and the performance of tools. At present, the test for the conditions of hand surface pressure is using physical prototype test methods. These test methods in the product development stage of handle tools need repeated trial, and test equipments are expensive, high cost and long cycle of the development design, and low efficiency.For the aims of improve efficiency and reduce costs, this paper attempts to research a virtual test approach, to access the surface pressure conditions when the hand grasp handle by the computer simulation. First, the adaptive handle-grasp action planning has been established, and the virtual process control of grasping movements has been implemented, on the understanding of the structural characteristics and movement relationships of the hand. Second, the three-dimensional model of the virtual hand for handle-grasp has been established, on the simplified of the hand structure. Then, the finite element model of the virtual hand has been created, its grasp movement and stress influence have been checked through simulation analysis, and a finite element analysis of grasp a simple handle has been done, pressure situation on the hand can be obtained. And the reasonable verification of the virtual test approach have been done, the virtual test approach is effective. At last, three virtual tests of handles-grasp of typical shape have been analyzed. The surface pressure conditions have been obtained, and evaluated.The paper provides a virtual test method for pressure situation of hand surface, and a novel pressure test approach for the development of hand tools. |
