Procedia manufacturing最新文献

Honeycomb materials are widely used as core layers of sandwich panels in the packaging, furniture, aviation, and space industry. To fulfill the varying requirements of the different applications, a wide range of materials, cell geometries, and cell sizes is used. In combination with comparably low stiffness, fragile cell walls, and large dimensions, the various properties make the automated gripping of honeycomb panels challenging. In this paper, a new concept for a soft gripper, based on adjustable threads, providing the flexibility and sensitivity needed for gripping honeycomb materials, is presented. Based on analysis and preliminary tests, a prototype is designed and built. A series of tests is performed to determine the optimal gripping parameters for different honeycomb materials, as well as to quantify the gripping force. The tests show the suitability of the concept for automated gripping of a wide variety of honeycomb types.

In case of conical worm production by conventional thread grinder, the fluctuation in angular velocity causes thread error. One possible way to eliminate the pitch error at the conical screw surface machining by shaft displacement is to design a drive pin that provides a constant pitch. In the course of our research, the examination of the machining of the conical worm surfaces by apex adjustment to eliminate the pitch fluctuation problem was carried out as a generalization of studies simulated with trigonometric relations in a particular case. The investigation was continued in a constructive geometric way with the aim of exploring universal mathematical relations in explicit forms in the mathematical kinematic model instead of the point series of the driver pin creator curve calculated in a given occurrence. The developed method makes exact design of the correct threading possible as a function of angular rotation in motion transfer under the given technology conditions, and thus expands the mathematical toolbar for innovative engineering design. Here we introduce the constructive geometric path supported by the algebraic toolbar, which also required affine and projective geometric relations in developing a solution that meets freely chosen expectations.

Companies around the world have sought to produce sustainable products and services with less impact. The impact produced by the COVID-19 pandemic showed that the supply Systems Product-Service (PSS) with an emphasis on sustainability has grown to become one of the main strategic approaches used. The existence of an automated framework that can assist designers in creating a PSS that encompasses the preparation of products and services simultaneously, from its initial stages, has become extremely important. Thus, the objective of this article is to develop a Framework capable of organizing the necessary information for the development of product and service in an integrated way, using the development of information architectures rationale, such as TOGAF, so that in all stages there is fluidity and there are no duplicity terms in its development. The use of information architecture development methods to develop the PSS structure presents a great opportunity to carry out its mapping, thus ensuring that the model is suitable to represent real-world situations.

Despite recent advantages, internal logistics for aircraft production is mainly performed manually. Missing or wrongfully loaded components can cause costly delays. Transforming delivery units into smart participants of a digitalized logistic chain has the potential to avoid such delays. In the scope of this work, we present a concept of a smart delivery unit for use in intralogistic processes on aircraft production sites. Its main functionality, the detection of loaded components and material, handles a high variety of identification principles that are defined by pre-existing processes. We therefore conceptualize smart sensor boards. Through a novel modularity structure, demand-driven equipment of these boards with different sensor types can be achieved. This includes AI-based, visual detection of components on delivery units. We display the versatility of our concept with a practical implementation based on low-cost sensors and demonstrate how our approach leads to demand-driven delivery units.

Effective inventory management has a direct influence on monetary savings, high customer service level and product quality and thus plays an essential role in a company’s economic and strategic performance. Forecasting and inventory models for aviation logistics are essential in commercial aviation. The objective of this paper is to study the problem of identifying the optimal order quantity of aircraft spare parts and the demand periods using the Order-Up-To (OUT) inventory model in conjunction with the Negative Binomial Distribution (NBD) and the (s, S) inventory model with Revised Power Approximation Method. These models are compared and contrasted via a real-world paradigm. The analysis reveals that the OUT inventory model in conjunction with the Poisson distribution allows ordering the lowest order quantity. However, the (s, S) inventory model with the Revised Power Approximation outperforms it in terms of average total inventory costs.

The article describes the results of identification and analysis of the environmental aspects of metal bonding technology. It was shown that in each of the stages of gluing operations, starting from surface preparation, through preparation of adhesive mass, application of the mass, joining, curing and finishing of the joint, negative aspects for the environment can be indicated. Two particularly problematic stages have been identified: the preparation of the surface before bonding and the preparation of the adhesive mass. These are initial stages, but they are characterised by different forms of human and environmental impact. A modification of the first stage was proposed as an alternative approach. The traditionally used mechanical treatment for steel and chemical treatment for aluminium alloys was replaced by laser treatment. The roughness and wettability of the laser-prepared surface were measured. The numerical results obtained for both the 25HM and X6Cr17 steels investigated, and the 2024 and 5083 aluminium alloys, lead to the conclusion that laser processing can satisfactorily replace environmentally burdensome technology. However, this replacement is not absolutely unconditional. In the following part of the article, it is shown that the use of lasers may involve different environmental aspects and health risks than before. The analysis concludes that new forms of risk should be taken into account when choosing a laser surface preparation technique. However, the best solution, which requires further research, is not only to eliminate chemicals from the surface preparation stage, but also adhesives.

Conventional processes like shearing dispose a lack in efficiency and formability to manufacture functional components with a high geometric variety. A possibility to allow the efficient and sustainable manufacturing is the application of innovative forming operations like orbital forming. Thus, a strain-hardened component with a load-adapted thickness profile can be manufactured in a single-stage process. Thereby, the control of the material flow could be identified as major challenge due to the three-dimensional stress and strain state. In order to reduce the parts weight and simultaneously guarantee the same level of performance, conventional steel is substituted by lightweight materials such as precipitation hardenable aluminum alloys. However, new challenges arise due to the reduced formability of aluminum compared to conventional steel. In recent research, the potential of a short-term heat treatment to enlarge the formability could be shown. The presented process locally reduces the materials strength, thus allowing a control of the material flow by the interaction between softened areas and areas, which offer the initial conditions. In this contribution, the influence on the formability of orbital formed components manufactured out of the precipitation hardenable aluminum alloy EN AW 6016 by a local short-term heat treatment is investigated. Different geometry-based heat treatment layouts are applied in order to maximize the thickening on different radial positions. The potential to enhance the formability is evaluated by comparing geometrical and mechanical properties of the components manufactured in the conventional process route and with a previous heat treatment. The analysis of radial cross-sections and the hardness distribution reveals the positive influence of the heat treatment but also points out the geometrical dependency of the effect due to the characteristic material flow in orbital forming.

Laser based directed energy deposition (DED) is a competitive method for repairing and remanufacturing metallic parts used in numerous industries including aerospace and biomedical. However, the numerous dynamic phenomena associated with the DED process often result in defects such as entrapped-gas pores, lack of fusion, and undesirable anisotropic properties. The entrapped-gas pore, being one of the most common issues, not only influences melt-pool dynamics but also reduces the fabrication quality and mechanical properties of parts fabricated by the DED process. To reduce and further understand this issue, the real-time observation of the pore formation process needs to be studied first. To directly observe the phenomena in the melt pool, high-speed techniques are needed because rapid solidification leads to rapid pore formation and movement. In-situ high-speed X-ray has been proven to be an effective method in investigating the melt pool dynamics and pore formation mechanisms in the laser powder bed fusion process, in which the fabrication process is quite different from that in DED. Here, the high-speed X-ray method is extended to study the formation of entrapped-gas pores. The real-time formation and quantitative analysis of pores under each set of processing parameters (particle velocity, laser power, and spot welding dwelling time of stationary laser) in the DED process are investigated. We found that the DED with a higher particle velocity (3.19 m/s) produced a smaller average pore size of 27.8 µm and a lower pore area fraction of 0.52%. The DED under lower laser power (156 W) generated a smaller average pore size of 20.3 µm and a lower pore area fraction of 1.94%. The shorter dwelling time (10 ms) benefited the decrease of both average pore size and pore area fraction.

Deep hole drilling process is extensively used in demanding applications, namely plastic injection moulding, oil and gas industry and automobile engines. This drilling process encounters problems such as improper chip evacuation, poor surface finish, roundness variation, and high tool wear, which affects the hole quality. To overcome these limitations, ultrasonic vibration-assisted deep hole drilling (UVADD) is performed in this work. The high-frequency vibrations were imparted into the ASTM A36 steel (workpiece) to induce reciprocating motion, which is mounted over a transducer. A special fixture arrangement was fabricated to hold the transducer in the drill bed. This helps to transfer the vibration to the workpiece. The machining performance of UVADD was analyzed by means of cutting force, tool wear, torque, hole quality, surface roughness, machining time and chip morphology, and the performances were also compared with the conventional deep hole drilling (CDD) process. Results suggested that a reduction in cutting force and torque was observed for UVADD. This is due to small discontinuous chips generated. Hole quality showed a drastic decrease in burr formation and surface roughness along with a uniform radius around the periphery. From the tool wear examination, it was also evident that no built-up edge formation occurred along the cutting edge owing to effective penetration of coolant and reduction in cutting temperature. This comprehensive analysis revealed that UVADD provided an enhancement in machining performance as compared to CDD.