Journal of Modern Processes in Manufacturing and Production
Volume:4 Issue: 2, Spring 2015

Most of the materials used in the industry of aero-engine components generally consist of titanium alloys. Advanced materials, because of their excellent combination of high specific strength, light weight and general corrosion resistance. In fact, chemical wear resistance of aero-engine alloy provides a serious challenge for cutting tool material during the machining process. The reduction in cutting temperature distributions leads to an increase in tool life and a decrease in wear rate. Hence, the chip morphology and segmentation play a predominant role in determining machinability and tool wear during the machining process. The result of low thermal conductivity and diffusivity of this alloy is in the concentration of high temperatures at the tool-work piece and tool-chip interface. Consequently, the chip morphology is very important in the study of machinability of metals as well as the study of cutting tool wear. Otherwise, the result will be accelerating tool wear, increasing manufacturing cost and time consuming.

A water jet machining is an industrial tool capable of cutting a wide variety of materials using a very high-pressure jet of water, or a mixture of water and an abrasive substance. This paper addresses the concept of the Intelligent knowledge base system (IKBS) for optimization of product design and manufacturing process for water jet machining in computer based concurrent engineering environment. The I KBS links with feature library. The design specification is acquired through a feature based approach. The IKBS links with material data base which holds attributes of more than 20 type of materials. It also links with abrasive data base which hold attributes of 8 types of abrasive, and also 4 type and size of machine. IKBS is also links with machine data base which hold machine parameters. For each design feature, IKBS provides information needed for design and manufacturing optimization. The IKBS can be used as an advisory system for designers and manufacturing engineers. It can be used as a teaching program for new water jet operators in computer based concurrent engineering environment.

In this article, modeling and optimization of power consumption of two–stage compressed air system has been investigated. To do so, the two – stage compressed air cycle with intercooler of FAJR Petroleum Company was considered. This cycle includes two centrifugal compressors, a shell, and a tube intercooler. For modeling of power consumption, actual compressors isentropic efficiencies and intercooler thermal effectiveness are calculated from experimental data. In these equations isentropic efficiency of compressors is a function of inlet temperature and thermal effectiveness of the intercooler is a function of inlet air temperature, inlet water temperature of the intercooler and inlet volumetric flow rate of the cycle. For optimization of power consumption, the Lagrangian method is used. Power consumption and isentropic efficiency of the first and second stage compressors, thermal effectiveness of the intercooler and entropy generation of compressors are considered as the objective function and optimization conditions, respectively. In comparison to the experimental data, the modeling provided suitable accuracy. The optimization effectively reduced the power consumption of the cycle, especially in summer, in a way that the minimum and maximum reduction was 2.9% and 9.6%, respectively.

In this paper, to simulate mechanical stress on the cutter bar of the harvesting combine during cutting of wheat stems, first, shearing strength of the stems was measured for various moisture content levels and cutting heights. After that the cutter bar of combine was simulated by Abaqus with the specified conditions. The results of the simulation showed that with increase in moisture content of stem, shear stress on the blade is increased up to 18% due to the viscous damping effect of the moisture of stem. On the other hand, with increase in cutting height, shear stress on the blade is decreased up to 12% because of the accumulation of less mature fibers at the lower levels of stems.

This paper proposes a simple but efficient technique to control 3D overhead crane. Load must track a desired path and not sway more than a reasonable range.The proposed method uses PID control for trolley to track the desired path and fuzzy control compensation to eliminate the load swing. Only the projection of swing angle is applied to design the fuzzy controller. No plant information of crane is necessary in this approach. Therefore, the proposed method greatly reduces the computational efforts. Effectiveness of the proposed method is illustrated through a simulated examp.

Operational failures in centrifuge pumps could be hydraulic or mechanical. However, most of these mechanical and hydraulic failures are connected cause of their operational nature and finding the right cause is due to considering numerous mechanical and hydraulic signs and parameters in pumps. On the other hand, due to non-linear and fluctuant behavior of pumps in the matter of time and not precise and clear data from a complicated system such as a petrochemical unit installations, investigating the failure possibilities in pumps by exact mathematical equations is so hard. However, the expert staff in maintenance could find the cause of failure by getting benefit of imprecise and verbal rules of "if-then" and the awareness of the non-clearance in system. However, it should be noted that this process takes time and also it is so dependent on the knowledge of expert staff, also human error can cause wrong decision-making and it declines reliability in the system. Therefore, this study is looking forward to find a collection of imprecise and verbal rules by using the reference book of "OREDA", also the pump handbook and the knowledge of expert staff in maintenance. With the acquisition of knowledge and Extraction of linguistic rules from taking effect between critical failure modes of mechanical and hydraulic parameters of process pump is created the relationship between these parameters and verbal rules, also by using a neural network of MLP category for the cases to train the neural network. Obtained results in companion with the average on accuracy, precision and recall parameters would be the approval of our method.