2nd World Conference on Mechanical Engineering

Subsequent to the design of the compact centrifugal compressor which is specifically intended to be used in aviation platforms, the process has been evaluated within the context of this study. A trade-off study matrix for future studies has been formed after making comparison between the design and the previous studies taking part in literature. The working fluid will be refrigerant. Properties such as thermodynamic properties and Global Warming Potential(GWP)-Ozone Depletion Potential(ODP) Values of the fluid have been taken into consideration during the selection process of the refrigerant. Some design and analysis softwares have been used in the part of conceptual design and R1233ZD has been selected as the refrigerant. Real-gas Computational Fluid Dynamic(CFD) analysis has been carried out with different cubic equations of state in the ANSYS CFX solver so as to figure out the most suitable solution method. These equations are named as “The Redlich Kwong”, “Soave Redlich Kwong”, and “Peng Robinson.” By being used the mentioned solution equations in the same compressor configuration, analysis also have been carried out with two gases having different characteristics. As a result of the 9 analysis carried out with three different refrigerants and three different solution equations mentioned above, the most accurate solution method has been selected by comparing the densities of the gases at different pressure and temperature points. The results have been analyzed with the selected equation. The results are about a trade-off study matrix presenting a comparison regarding the compact centrifugal compressor operating with the refrigerant to be designed and density errors that is between analysis and real. This comparison is between some design parameters determined before the design and their values in the literature.

In the automotive industry, studies on improved safety attributes have received increasing attention in recent years. In case of a design change in the field of safety, compliance with the regulations is essential and studies are carried out in this direction without compromising on mechanical properties. In the present study, after the design change of the luggage bar part of the rear row triple seats in commercial vehicles, passenger security-based analyzes were characterized and the effect of different computer-aided engineering (CAE) models was examined. Based on this, the ECE R17 Luggage retention test was performed using the Rigid Coupling model and the Hexa element model. The test models were compared and the physical test was performed for correlation purposes. After the analysis, it was determined that the Hexa element model was appropriate in terms of correlation and surface-surface contact between the seat and the luggage bar, beam-to-surface contact for the edge surfaces between the seat leg and surface-surface contact parameters for the contact surfaces were used in the relevant modeling. After finite element analysis (FEA) analysis, tearing was detected in the pin of the structure, and a correlation was achieved in the physical test. Design changes were made in the relevant area, but after repeated analysis, various design changes were made in the structure when it was transmitted to different regions such as high-stress wire and slot parts. After the analysis, the renewed design has successfully passed the ECE R17 regulation by providing without increasing weight. No deformation or breakage was observed in the physical test performed after the prototype production.

Military live-fire exercises are carried out to make practical experiments on defence hardware. Rockets targets are used to imitate real rockets and missiles. RT-400M is a medium-range rocket target designed and developed to attain a maximum range of 20 km and an altitude of 10 km. This research shows the procedure carried out during the process of research, design, development and testing. Based on the requirement ballistic analysis of the different possible arrangements of a rocket motor is performed numerically. A rocket with two and four motors is analyzed, and four motor variant is chosen for the final model. The aerodynamic analysis is performed to make shape modifications and maintain the stability of the rocket during the entire trajectory. Subsonic and supersonic speed analysis is performed to obtain the drag and moments. Based on the research data, the experimental model is developed for the live fire exercise to compare with the numerical data.

There is intense competition for market share between multinational automobile organizations (MAO) in areas such as innovative technology, branding, and of course total global vehicle sales. To precisely forecast production planning for vehicle production, accurate internal vehicle sales estimates are vital to production planning as both overproduction and underproduction can ruin the bottom line if it doesn’t match consumer demand. While increasing the total number of vehicles sold international vehicles internationally is a major goal of any MAO, sheer vehicle sales may not enhance the bottom line of an automobile organization. Accurate sales must match forecasted production schedules, which are created over one year in advance, to achieve the most earnings. With international supply chains becoming more volatile since the onset of the global pandemic, it is more important than ever that sales correspond to projected production schedules. Since supply chain scheduling is done over a year in advance, the most successful MAOs spend much time and resources on these forecasts so that parts, machining, energy usage, and training can be planned accordingly. This presentation will examine the effects of national tariff rates, exchange rates, and changes in GDP on imported vehicles in order to help MAOs more accurately predict the likelihood of imported vehicle sales in industrialized countries. This study built models based on economic variables that affect the vehicle sales of imports to better predict the likelihood of sales of imported vehicles in industrialized countries. Automobile imports were modeled as the dependent variable with tariff rate, exchange rate, and GDP as the independent variables using a repeated measures design. Variables included: GDP, Imported vehicles, Tariffs (ad valorem duties), exchange rates, for ten industrialized countries. From the table below, the fixed effect parameter estimates for the full model are show in the table below. Significant effects for Exchange Rate (p = 0.0005) and GDP (p = 0.026) were found, representing 1.37% and 1.95% increases in Exports per 1% change, respectively. Tariff Rate was non-significant (p = 0.7958).

This paper introduces a comprehensive set of numerical tools employed for the preliminary design of ramjet missiles based on liquefying fuels. The development process follows the guidelines set forth by the European Cooperation for Space Standardization. The Brazilian Navy has been considered as the leading customer, providing the necessary requirements for the surface-to-surface missile system. The main code employed in this study employs a two-degree of freedom model for flight mission analysis, encompassing the ascending, cruising, and descending phases of a supersonic missile powered by a solid-fuel ramjet. Additionally, an internal ballistic code aids in the design of the ramjet engine. Correlations published in existing literature for various missile help define the basic geometry and mass of warhead, guidance-control and integrated propulsion for a given system mission. Warhead and guidance-control masses are kept constant while the booster and ramjet engines are iteratively upgraded. Through the execution of ECSS phase zero, the results demonstrate the development of a medium-range supersonic missile whose ramjet has 253 kg, 4,000 mm in length, with an external diameter of 300 mm. This missile carries a high explosive payload of 100 kg with a range exceeding 160 km in less than four minutes. During the cruising phase, the missile operates at altitudes of about 13,000 m, achieving speeds up to 2.8 Mach.

This paper presents a case study on the behavior of a manipulation tool, known as a Gripper, attached to an articulated robot in the condition of immediate stop. The goal is to demonstrate how structural analysis can be carried out, taking into account all dynamic aspects of the Gripper's behavior. The study uses Ansys version 18 to perform a series of analyses, including kinematic, modal, harmonic, transient, and explicit analyses, with simplifications made to the geometry and material of the system. The results show that the explicit analysis best represents the propagation of vibration along the structure, and the transient analysis with an implicit solver is not recommended due to significant convergence difficulties. The study concludes that the response corresponds to what actually happened in the welding cell and that the failure of the Gripper was almost inevitable due to poor welding and the abrupt stop at a point where the robot reached its maximum speed.

Composite materials, which become rather substantial in the automotive industry by the reason of carbon footprint and lightweight subjects, have gained wide attention in various scientific fields in recent years. This paper represents the lightweight design and mechanical characterization of the fender part as a composite, instead of the traditional metal fender on heavy trucks. In this direction, glass fiber-reinforced composite material was utilized in compliance with the plastic injection method. By conducting the design studies for the composite fender, it is targeted to procure lightweight, mechanical properties, dynamic and static loads. Based on this, the finite element analysis (FEA) method was performed in order to characterize the existing metal structure, modal analysis and fatigue-stress life estimation analyses were performed on the fender initially. Before modeling the composite part, the material characterization was conducted and the tensile test curves of the composite material were obtained. Thereupon, appropriate fender design for composite material has been developed by considering mechanical properties. After the design, the finite element model was constituted on the structure and finite element analysis was accomplished. As part of the analysis, improvements were made in the composite design by characterizing the stress, strain and displacement distributions. After the FEA, the fender holder part was redesigned as a hybrid composite. In the verification stage of the final design, modal analysis occurred due to examining the out-of-limit resonance at 23 °C and 60 °C. Besides, resistance against dynamic loads was analyzed due to investigating the material’s behavior under g loads. After the composite design met the relevant limits on FEA; prototype production was carried out. Regarding the final product, 60% weight reduction was achieved.

Fatigue failure is the most reason for materials failure due to stresses under the strength limits of materials. The fatigue properties of composite materials can be improved by using high properties reinforcements such as carbon, Kevlar, and glass fibers. Several procedures can be used to increase the stiffness, strength, fatigue strength, and fatigue life composite materials. These procedures such as applying pre-stress to the fibers during curing porcess , and/or adding Nanoparticles like Multi-wall Carbon Nanotubes (MWCNTs) to the resin of the composite. This research studied experimentally the effect of adding MWCNTs that had high mechanical properties with different percentage ratios (0.5, 1 and 2wt.%) to the epoxy and composite(epoxy +carbon fiber with volume fraction of 30%). The pre-stress of (2.5, 5, 7.5, and 10MPa) applying to the carbon fibers during the curing process of hand layout of composite to produce residual stresses inside the resin of composite that may gave extra stiffness to the fibers. The fatigue test results of fully reversed bending stress with (R= -1) showed maximum increasing ratio in fatigue life for the epoxy reached 350% when adding 1wt.% MWCNTs, while the improvement ratio for hybrid composite reaches 2850% when adding 1wt.%MWCNTs with fiber pre-stressing value of 10MPa. The adding MWCNTs to the resine with ratio of 2wt% will decrease the fatigue life of the composite due to the agglomerate of Nanomaterials inside the resin that make it been as weakness points and cant transfer the load between MWCNTs , and that reduces the positive effect of adding MWCNTs.