Manufacturing Engineering

The rapid growth of the automotive industry was also followed by growth in subsidiary companies. One of the subsidiary companies is a company that produces auto parts such as wheels. Sales volume in 2021 increased to more than 2 million products while for 2022 to April it was more than 1 million products. High demand is not accommodated due to inadequate production capacity, one of which is the machining area. This study aims to increase efficiency by redesigning the layout of the factory which is considered to increase production results in the machining area. The method used in this research is Block Layout Overview with Computerized Planning using Logic and Algorithm (Blocplan). The results showed that the redesign of the machining area could reduce stagnation by adding 1 unit of multi drill machine. Relayout in the machining area can reduce 93” time stagnation for the K2SA rear ABS type which can produce 2 outputs at once. The delay in the machining area can be reduced from 4,86...

In the forging industry typical in the 21st century, economical production requires environment-friendly manufacturing of integrated and complicated products of larger and larger masses. Difficulties to be solved require effective researches, technological developments and cost analyses. Most frequently, cost analyses call the attention to energy demand of forging, to tool costs and to the efficiency of raw material usage. Preservation and enhancement of competitiveness based on environment-friendly technological solutions are one of the most important challenges for the forging industry in the 21st century. Our case study presents BY (The Best Yield) treatment technology of a planetary carrier developed in the RABA forging plant. Development of the basic technology required integrated application of CAD (Computer Aided Design) – CAE (Computer Aided Engineering) and a test method using thermographic camera. Integration of IT (Information Technology) systems created a new design meth...

In the past two decades, rapeseed farming has garnered attention, because it offers the possibility of attaining self-sufficiency in the production of edible oil, which is a strategic product for Iran. Therefore, the overarching goal of this research was to provide sound strategies to further the development of rapeseed farming and to increase the sustainability and productivity of rapeseed production systems. Progress toward this goal was made by assessing subsistence and commercial rapeseed production systems in Khorramabad, Iran during the 2017–2018 crop year using both emergy and economic indices. The calculated values of the ESI*, %R, ELR, and ELR* indices showed the higher ecological sustainability of the subsistence farming system compared to the commercial system of rapeseed production. According to these indices, the main reason for the lower sustainability of the commercial rapeseed production system was the large amount of soil organic matter that was lost per unit input of nonrenewable resources used. A large emergy exchange ratio in favor of the buyer, the increased environmental sustainability when the market impact is considered, the lower emergy consumption per unit of output, and the higher productivity of the production factors all reflect the relative advantage of the commercial system based on the indices of EERY, EISD, UEV, and total factor productivity (TFP), respectively. Hence, our findings revealed that in the commercial rapeseed production system, the ecologic sustainability of the system can be improved drastically by employing scientific solutions for the comprehensive management of the production ecosystems, especially through the amelioration of soil organic matter and prevention of its loss. Besides improving the farmers’ technical knowledge, the integration of small lots into the production system is recommended for improving the economic sustainability of the subsistence production system.

In this analysis of the prehistoric global nitrogen cycle, relationships between the emergy per unit mass and the mass concentration of nitrogen were examined. A monotonic increase in the emergy per unit mass (the specific emergy) as a function of increasing material concentrations is predicted by energy hierarchy principles and was observed in the data. This pattern is expected when energy transformation is accompanied by an increase in the concentration of material in higher transformity units. Among nitrogen species in the troposphere a different pattern was observed, where transformity and the emergy per unit mass are greater for the more reactive but lower concentration nitrogen species. In this case, lightning discharges create nitrogen species of higher transformity by breaking the stable triple bond of diatomic nitrogen and increasing its chemical reactivity. The nitrogen flows through living systems are arranged in an energy capturing order-disorder loop upon which a trophi...

High strength low alloy (HSLA) steels, used in a wide variety of applications as structural components are subjected to cyclic loading during their service lives. Understanding the cyclic deformation behavior of HSLA steels is of importance, since it affects the fatigue life of components. This paper combines experiments with finite element based simulations to develop a crystal plasticity model for prediction of the cyclic deformation behavior of HSLA-50 steels. The experiments involve orientation imaging microscopy (OIM) for microstructural characterization and mechanical testing under uniaxial and stress–strain controlled cyclic loading. The computational models incorporate crystallographic orientation distributions from the OIM data. The crystal plasticity model for bcc materials uses a thermally activated energy theory for plastic flow, self and latent hardening, kinematic hardening, as well as yield point phenomena. Material parameters are calibrated from experiments using a g...

A microstructure sensitive criterion for dwell fatigue crack initiation in polycrystalline alloy Ti-6242 is proposed in this paper. Local stress peaks due to load shedding from time dependent plastic deformation fields in neighboring grains are held responsible for crack initiation in dwell fatigue. An accurately calibrated and experimentally validated crystal plasticity finite element (FE) model is employed for predicting slip system level stresses and strains. Vital microstructural features related to the grain morphology and crystallographic orientations are accounted for in the FE model by construction of microstructures that are statistically equivalent to those observed in orientation imaging microscopy scans. The output of the finite element method model is used to evaluate the crack initiation condition in the postprocessing stage. The functional form of the criterion is motivated from the similarities in the stress fields and crack evolution criteria ahead of a crack tip an...

The properties of recycled styrene-butadiene rubber (SBR) powder with polystyrene (PS) have been studied as a function of compounding conditions in an internal batch mixer. In particular, the effect of temperature (160–220°C), rotor speed (30–120 rpm), homogenization time (3–9 min), components introduction order, surface treatment of SBR powder with a PS/tetrahydrofuran (THF) solution, and addition of a coupling agent (styrene-ethylene-butylene-styrene, SEBS) were studied. The compounds were then compression moulded and samples were prepared to measure their hardness, tensile properties (modulus, strength and elongation at break) and impact strength. Morphological analysis via scanning electronic microscopy (SEM) on selected samples was also performed to determine the interfacial state between the components. From all the results obtained, an optimisation procedure is proposed allowing the best compound to be determined as a function of final application.

This work presents an application of genetic algorithms to assembly sequence planning. This problem is more difficult than other sequencing problems that have already been tackled with success using these techniques, such as the classic Travelling Salesperson Problem (TSP) or the Job Shop Scheduling Problem (JSSP). It not only involves the arranging of tasks, as in those problems, but also the selection of them from a set of alternative operations. And/Or graphs are used as an efficient structure for the representation of all the possible assembly plans. Thus the selection process results in a search in the And/Or graph of the product. Two representations of solutions are compared in this work. The first one uses a binary chromosome that corresponds to an ordering of the enumeration of all possible assembly sequences. Conventional genetic operators are used with this representation. In the other one a chromosome represents a sequence of tasks, compatible with the ordering constraint...

Controlling the transfer of ink to the substrate is a key requirement of the flexographic printing process. Its ability to transfer ink from the image carrier to the substrate at low pressures enables the process to be used for the production of printed matter using pressure-sensitive materials. These can range from substrates where high pressures can damage surface structure (e.g. corrugated board), to specialist inks, which can be damaged by the high shearing action associated with other volume print processes. This paper evaluates the effect of pressure changes on print quality for different anilox specifications and line rulings on the plate. Data collected from an experimental print trial were used to quantify the effects of anilox roll specifications, dot pitch, and plate-to-substrate engagement on the reproduction of both a continuous ink film and the formation of discrete halftone dots. The ink-carrying volume of the cells of the anilox roll was shown to have the greatest in...