The multi-impact characteristics and failure mechanism of two kinds of automotive engine chain made in China are studied through engine assembly and road-drive tests. The worn surface morphologies of rubbing area betw...The multi-impact characteristics and failure mechanism of two kinds of automotive engine chain made in China are studied through engine assembly and road-drive tests. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine chain is fatigue wear, and its failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. In addition, the material, hot-treatment method and shaping technique for roller have a great influence upon the resistance to multi-impact. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technique are the effective method to increase its resistance to multi-impact.展开更多
That flow is the common feature of substance flow and fluid flow is the viewpoint emphasized in the paper. Some notes on fluid mechanics, including the two approaches of fluid flow description, were given. The concept...That flow is the common feature of substance flow and fluid flow is the viewpoint emphasized in the paper. Some notes on fluid mechanics, including the two approaches of fluid flow description, were given. The concepts of the chain and the chain group of product life cycles, which are essential for understanding the specific features of substance flow, were advanced. Taking the specific feature of substance flow into consideration, on the analogy of the two approaches in fluid mechanics, two approaches of substance flow analysis, i.e. L method and E model, were formulated. Illustrative models of steady and unsteady substance flow were sketched by both methods, and comparison between them was made in general.展开更多
To solve the inventory coordination model in a multi-stage, multi-customer supply chain, this paper first analyzes the third model (integer powers of two multipliers at each firm) studied by Moutaz Khouja (2003), ...To solve the inventory coordination model in a multi-stage, multi-customer supply chain, this paper first analyzes the third model (integer powers of two multipliers at each firm) studied by Moutaz Khouja (2003), and the authors take a numerical example to prove that the third model is irrational to miss feasible solution. Then this paper puts up a new improved model (integer multiplier at each firm), and takes the example to prove it gives better results than the integer powers of two multipliers at each firm.展开更多
基金This project is supported by National Innovation Foundation for TechnologyBased Firms, China (No.01C26213300872).
文摘The multi-impact characteristics and failure mechanism of two kinds of automotive engine chain made in China are studied through engine assembly and road-drive tests. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine chain is fatigue wear, and its failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. In addition, the material, hot-treatment method and shaping technique for roller have a great influence upon the resistance to multi-impact. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technique are the effective method to increase its resistance to multi-impact.
文摘That flow is the common feature of substance flow and fluid flow is the viewpoint emphasized in the paper. Some notes on fluid mechanics, including the two approaches of fluid flow description, were given. The concepts of the chain and the chain group of product life cycles, which are essential for understanding the specific features of substance flow, were advanced. Taking the specific feature of substance flow into consideration, on the analogy of the two approaches in fluid mechanics, two approaches of substance flow analysis, i.e. L method and E model, were formulated. Illustrative models of steady and unsteady substance flow were sketched by both methods, and comparison between them was made in general.
文摘To solve the inventory coordination model in a multi-stage, multi-customer supply chain, this paper first analyzes the third model (integer powers of two multipliers at each firm) studied by Moutaz Khouja (2003), and the authors take a numerical example to prove that the third model is irrational to miss feasible solution. Then this paper puts up a new improved model (integer multiplier at each firm), and takes the example to prove it gives better results than the integer powers of two multipliers at each firm.