Advanced Materials Research Vols. 341-342

Abstract: Rapid tooling technology is regarded as an important method of reducing the cost and time to market in a new product development process. Silicone rubber mold is frequently employed in the indirect tooling. Based on green manufacturing, an environment friendly process for making large size silicone rubber is developed and implemented in this work. This method provides a new, simple, and green manufacturing to produce large size silicone rubber mold without loss of dimensional accuracy, geometrical accuracy, and surface roughness. The advantages of this method include high yields of the mold fabrication, reducing the cost in the mold fabrication, and environmentally conscious manufacturing. The saving in the cost of the rapid tooling is up to 66.41%.

Abstract: The complexity of Printed Circuit Boards (PCBs) has increased dramatically over the last three decades with the development of surface mount technology (SMT). The typical manufacture of rigid multilayer PCB contains many process procedures, which makes manufacture and application much more challenges. This paper focuses on some typical PCB related failures. Recommendations are provided on optimizing PCB manufacture process and material application. Microvia crack, black pad, galvanic attack, pad design, conductive anodic filament and pad crater are presented in detail.

Abstract: Limit load analysis of defect free thick walled pipes and cylinders subjected to internal pressure and combined internal pressure and axial loading is commonly performed as part of integrity assessment procedures for transmission pipelines and pressure vessels across the industry. Moreover the potential impact of environmental assisted or accidental damage that result in creation of surface defects and consequently affects the ability of vessel to withstand the applied loading conditions. This paper attempts to demonstrate the effect of surface defects on the limit load of cylinders by use of finite element method. ABAQUS software has been used for FE analysis and modeling. Approximate analytical solutions for benchmark model have been used for validation/verification of numerical results.

Abstract: The field of mine hoist in the coal mine has an important role, its relationship with the safe operation of coal mine production safety and the lives of many miners. This article of mine hoist began to study the current situation, put forward specific measures for improvement. And the introduction of PLC control system to improve the performance of mine hoist. In this paper, the specific principles of experimental program with the specific design, the study proved of great economic and practical significance.

Abstract: The main drawback of the method proposed by Marciniak and Kuczynski for prediction of the limit strains in sheet metal forming processes is requirement of an experimental point of the forming limit curve (FLC) in order to calibrate the curve. The purpose of this work is to introduce a new method to calibrate the FLC using the M-K model in which no experimental data is needed. To achieve this goal, many experimental FLCs were collected from the literature and the values of the initial inhomogeneity factors were determined for them with trial and error aproach. Using these data, an empirical law was developed to predict the value of inhomogeneity factor. The resultant curves show good agreement with the experiments.

Abstract: The failure mechanism of tungsten matrix composite was studied with microscale numerical simulation. The results show that high strength tungsten particles are the real loading elements of composite, its strength level embodies the whole property of the composite to some extent. The real stress in tungsten particles is much higher than the external load, so failure may take place when the external load is less than the theoretical strength of tungsten particles.

Abstract: This paper introduces the principle and characteristic of extrusion tapping of internal thread, presents the simplified mechanical model of extrusion tapping firstly. Then generalizes the key technology of extrusion tapping and their influencing law on tapping torque and thread forming quality, such as extrusion tap type, lead hole diameter, tapping speed and friction. Finally, numerical analysis on the key technology of extrusion tapping are conducted based on DEFORM-3D, the results show that the effect of lead hole diameter and friction on tapping torque are obvious, the effect of extrusion tap type and tapping speed on tapping torque are next and this effect degree is related to the stress-strain relation of workpiece material under different strain-rate closely. These researches will contribute to the right selection of workpiece material, extrusion tap type, lead hole diameter, tapping speed and lubrication of extrusion tapping of internal thread in practical manufacture.

Abstract: Caterpillar walk agency is the supporting a large walk machinery, used to support the weight of the whole machine, inherit institution in engineering work force produces in the process, and complete the machine in March, backward, also, the mobile. Homework Therefore, to average large engineering machinery chassis general design into tracked drive structure, and tracked down the vertical center symmetrical layout. This paper mainly studied and discussed crawler walks the organization design principles and exercise stress analysis, summarized the influence factors of walking organization for the future, the design of the machine can achieve reasonable structure, safe and reliable, action flexible have laid a good foundation.

Abstract: The adopted strategy to overcome the housing shortage crisis in Iran is the mass production. The way forward to accelerate the mass production, is adopting the industrial building systems with the increased prefabrication. One of the most optimal new building systems is Lightweight Steel Framing (LSF) Technology. Parand Residential Complex as the first serious project to industrialize the construction processes in Iran is facing the various problems during the processes of manufacture and execution of LSF components. The research aim is to offer an optimized model for manufacturing and execution processes of LSF Technology in the constructive projects which in it the deficiencies are compensated and strengths are intensified. So, case-studies and combined strategies has adopted as research method and based on it, the manufacture and execution processes of LSF technology in the case-study, were taken into consideration to recognize the existing advantages and disadvantages. The results of the research show that disadvantages of the manufacture and execution processes can be improved into one combined model. Finally, with offering four strategies to compensate the deficiencies and three strategies to intensify the strengths, the paper develops a model to coordinate the processes of manufacturing and execution in LSF technology in building design and construction.

Abstract: The usual hydraulic pump station pumps the general use of quantitative supply voltage level or constant pressure, using the corresponding control valve speed to adapt to work requirements, when the hydraulic system is intermittent or low-load condition, a large number of high-pressure oil through regulator overflow Back to the tank overflow valve, causing a great deal of energy consumption, when the hydraulic system requires a large flow of oil, it will result in a short time for the fluid system for liquid inadequate and under-voltage phenomenon. To solve this problem, we propose to improve the program, and conducted the analysis and comparison of several options to determine the source of energy-saving adaptive overall scheme of oil, its reasonable design, implementation of the automatic adaptive functioning, energy loss Small, the effect is significant.