1,084 research outputs found
COMPUTATIONAL ANALYSIS OF FEASIBILITY AND UTILITY OF DIRECT-ADHESION POLYMER-TO-METAL HYBRID TECHNOLOGIES FOR USE IN LOAD BEARING BODY-IN-WHITE AUTOMOTIVE COMPONENTS
Traditionally, metals and plastics are fierce competitors in many automotive engineering applications. This paradigm is gradually being abolished as the polymer-metal-hybrid (PMH) technologies, developed over the last decade, are finding ways to take full advantage of the two classes of materials by combining them into a singular component/sub-assembly. By employing one of the several patented PMH technologies, automotive original equipment manufacturers (OEMs) have succeeded in engaging flexible assembly strategies, decreasing capital expenditures and reducing labor required for vehicle manufacture. The basic concept utilized in all PMH technologies is based on the fact that while an open-channel thin-wall sheet-metal component can readily buckle under compressive load, with very little lateral support, provided by a thin-wall rib-like injection-molded plastic subcomponent, the buckling resistance (and the stiffness) of the component can be greatly increased (while the accompanied weight increase is relatively small). In the present work, the potential of direct-adhesion PMH technologies for use in load-bearing structural automotive components is explored computationally. Within the direct adhesion PMH technology, load transfer between stamped sheet-metal and injection-molded rib-like plastic subcomponent is accomplished through a variety of nanometer-to-micron scale chemical and mechanical phenomena which enable direct adhesion between the two materials. Multi-disciplinary computations are carried out ranging from: (a) computational investigation of the sheet-metal stamping process including determination of the residual stresses and the extent of stamped-component warping; (b) computational fluid mechanics of the filling, packing and cooling stages of the injection-molding process including determination of flow-induced fiber orientation in the molded plastic and the extent of residual stresses and warping in the injection-molded sub-component: and (c) structural-mechanics computational investigation of the effect of injection-molded component residual stresses and warping on their ability to withstand thermal loading encountered in the paint shop and mechanical in-service loading. The results obtained revealed that a minimal level of the polymer-to-metal adhesion strength (5-10MPa) must be attained in order for the direct-adhesion PMH technologies to be a viable alternative in the load-bearing body-in-white (BIW) components. In the present work, also various PMH approaches used to promote direct (adhesive-free) adhesion between metal and injection-molded thermoplastics are reviewed and critiqued. The approaches are categorized as: (a) micro-scale polymer-to-metal mechanical interlocking; (b) in-coil or stamped-part pre-coating for enhanced adhesion; and (c) chemical modifications of the injection-molded thermoplastics for enhanced polymer-to-metal adhesion. For each of these approaches their suitability for use in load-bearing BIW components is discussed. In particular, the compatibility of these approaches with the BIW manufacturing process chain (i.e. (pre-coated) metal component stamping, BIW construction via different joining technologies, BIW pre-treated and painting operations) is presented. It has been found that while considerable amount of research has been done in the PMH direct-adhesion area, many aspects of these technologies which are critical from the standpoint of their use in the BIW structural applications have not been addressed (or addressed properly). Among the PMH technologies identified, the one based on micro-scale mechanical interlocking between the injection-molded thermoplastic polymer and stamped-metal structural component was found to be most promising. Lastly, the suitability and the potential of various polymer-powder spraying technologies for coating metal stampings and, thus, for enhancing the polymer-to-metal adhesion strength in direct-adhesion PMH load-bearing automotive-component applications is considered. The suitability of the spraying technologies is assessed with respect to a need for metal-stamping surface preparation/treatment, their ability to deposit the polymeric material without significant material degradation, the ability to selectively overcoat the metal-stamping, the resulting magnitude of the polymer-to-metal adhesion strength, durability of the polymer/metal bond with respect to prolonged exposure to high-temperature/high-humidity and mechanical/thermal fatigue service conditions, and compatibility with the automotive BIW manufacturing process chain. The analysis revealed that while each of the spraying technologies has some limitations, the cold-gas dynamic-spray process appears to be the leading candidate technology for the indicated applications
The Science and Technology of 3D Printing
Three-dimensional printing, or additive manufacturing, is an emerging manufacturing process. Research and development are being performed worldwide to provide a better understanding of the science and technology of 3D printing to make high-quality parts in a cost-effective and time-efficient manner. This book includes contemporary, unique, and impactful research on 3D printing from leading organizations worldwide
Process Parameter Optimization of FFF 3D Printed Parts
This work aimed to create a Metal Additive Manufacturing technique, namely Fused Filament Fabrication (FFF), to find the ideal parameters for the printing of 316L stainless steel. The work consisted of adapting and developing the process parameters of FFF to produce tensile specimens. These parameters included the infill pattern, density, printing angle and support structures. In addition, several tests were done, like tensile, surface roughness, and microscopic analysis, to validate the imposed parameters.
After gathering the best parameters, a part from the automotive industry was printed to optimise the parameters, and cost analysis was compared with SLM technology. Thus, in this dissertation, the process parameter optimization of the FFF technology was made
Life Cycle Impact of Different Joining Decisions on Vehicle Recycling
Stricter vehicle emission legislation has driven significant
reduction in environmental impact of the vehicle use phase
through increasing use of lightweight materials and
multi-material concepts to reduce the vehicle mass. The joining
techniques used for joining multi-material designs has led to
reduction in efficiency of the current shredder-based recycling
practices. This thesis quantifies this reduction in efficiency
using data captured from industrial recycling trials.
Life Cycle Assessment has been widely used to assess the
environmental impact throughout the vehicle life cycle stages.
Although there is significant research on material selection or
substitution to improve the vehicleâs carbon footprint, the
correlation between multi-material vehicle designs and the
material separation through commonly used shredding process is
not well captured in the current analysis. This thesis addresses
this gap using data captured from industrial trials to measure
the influence of different joining techniques on material
recycling efficiencies. The effects of material degradation due
to joining choices are examined using the life cycle analysis
including exergy losses to account for a closed-loop system. The
System Dynamics approach is then performed to demonstrate the
dynamic life cycle impact of joining choices used for new
multi-material vehicle designs.
Observations from the case studies conducted in Australia and
Europe showed that mechanical fasteners, particularly machine
screws, are increasingly used to join different material types
and are less likely to be perfectly liberated during the
shredding process. The characteristics of joints, such as joint
strength, material type, size, diameter, location, temperature
resistance, protrusion level, and surface smoothness, have an
influence on the material liberation in the current sorting
practices. Additionally, the liberation of joints is also
affected by the density and thickness of materials being joined.
The life cycle analysis including exergy losses shows a
significant environmental burden caused by the amount of
impurities and valuable material losses due to unliberated
joints. By measuring the influence of joints quantitatively, this
work has looked at the potential of improving the quality of
materials recycled from ELV to be reused in a closed-loop system.
The dynamic behaviours between the joining choices and their
delayed influence on material recycling efficiencies from the
life cycle perspective are performed using the data from case
studies. It shows that the short-term reduction in environmental
impact through multi-material structures is offset over the
long-term by the increasing impurities and valuable material
losses due to unliberated joints. The different vehicle recycling
systems can then be resembled using two widely known system
archetypes: âFixes that Failâ and âShifting the Burdenâ.
Despite the adoption of more rigorous recycling approaches, the
life cycle impact of different joining techniques on vehicle
recycling continue to exist. The enactment of strict regulations
in current ELV recycling systems is unable to solve the
underlying ELV waste problem, and only prolongs the delay in
material degradation due to joining choices. This work shows that
the choice of joining techniques used for multi-material vehicle
designs has a significant impact on the environmental performance
during the ELV recycling phase
NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 34)
Abstracts are provided for 124 patents and patent applications entered into the NASA scientific and technical information systems during the period July 1988 through December 1988. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application
Engineering for a changing world: 60th Ilmenau Scientific Colloquium, Technische UniversitÀt Ilmenau, September 04-08, 2023 : programme
In 2023, the Ilmenau Scientific Colloquium is once more organised by the Department of Mechanical Engineering. The title of this yearâs conference âEngineering for a Changing Worldâ refers to limited natural resources of our planet, to massive changes in cooperation between continents, countries, institutions and people â enabled by the increased implementation of information technology as the probably most dominant driver in many fields. The Colloquium, supplemented by workshops, is characterised but not limited to the following topics: â Precision engineering and measurement technology Nanofabrication â Industry 4.0 and digitalisation in mechanical engineering â Mechatronics, biomechatronics and mechanism technology â Systems engineering â Productive teaming - Human-machine collaboration in the production environment The topics are oriented on key strategic aspects of research and teaching in Mechanical Engineering at our university
The 1st Advanced Manufacturing Student Conference (AMSC21) Chemnitz, Germany 15â16 July 2021
The Advanced Manufacturing Student Conference (AMSC) represents an educational format designed to foster the acquisition and application of skills related to Research Methods in Engineering Sciences. Participating students are required to write and submit a conference paper and are given the opportunity to present their findings at the conference. The AMSC provides a tremendous opportunity for participants to practice critical skills associated with scientific publication. Conference Proceedings of the conference will benefit readers by providing updates on critical topics and recent progress in the advanced manufacturing engineering and technologies and, at the same time, will aid the transfer of valuable knowledge to the next generation of academics and practitioners.
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The first AMSC Conference Proceeding (AMSC21) addressed the following topics: Advances in âclassicalâ Manufacturing Technologies, Technology and Application of Additive Manufacturing, Digitalization of Industrial Production (Industry 4.0), Advances in the field of Cyber-Physical Systems, Virtual and Augmented Reality Technologies throughout the entire product Life Cycle, Human-machine-environment interaction and Management and life cycle assessment.:- Advances in âclassicalâ Manufacturing Technologies
- Technology and Application of Additive Manufacturing
- Digitalization of Industrial Production (Industry 4.0)
- Advances in the field of Cyber-Physical Systems
- Virtual and Augmented Reality Technologies throughout the entire product Life Cycle
- Human-machine-environment interaction
- Management and life cycle assessmen
Index to NASA Tech Briefs, 1972
Abstracts of 1972 NASA Tech Briefs are presented. Four indexes are included: subject, personal author, originating center, and Tech Brief number
Optimization with artificial intelligence in additive manufacturing: a systematic review
In situations requiring high levels of customization and limited production volumes, additive manufacturing (AM) is a frequently utilized technique with several benefits. To properly configure all the parameters required to produce final goods of the utmost quality, AM calls for qualified designers and experienced operators. This research demonstrates how, in this scenario, artificial intelligence (AI) could significantly enable designers and operators to enhance additive manufacturing. Thus, 48 papers have been selected from the comprehensive collection of research using a systematic literature review to assess the possibilities that AI may bring to AM. This review aims to better understand the current state of AI methodologies that can be applied to optimize AM technologies and the potential future developments and applications of AI algorithms in AM. Through a detailed discussion, it emerges that AI might increase the efficiency of the procedures associated with AM, from simulation optimization to in-process monitoring
Applications and multidisciplinary perspective on 3D printing techniques: Recent developments and future trends
In industries as diverse as automotive, aerospace, medical, energy, construction, electronics, and food, the engineering technology known as 3D printing or additive manufacturing facilitates the fabrication of rapid prototypes and the delivery of customized parts. This article explores recent advancements and emerging trends in 3D printing from a novel multidisciplinary perspective. It also provides a clear overview of the various 3D printing techniques used for producing parts and components in three dimensions. The application of these techniques in bioprinting and an up-to-date comprehensive review of their positive and negative aspects are covered, as well as the variety of materials used, with an emphasis on composites, hybrids, and smart materials. This article also provides an updated overview of 4D bioprinting technology, including biomaterial functions, bioprinting materials, and a targeted approach to various tissue engineering and regenerative medicine (TERM) applications. As a foundation for anticipated developments for TERM applications that could be useful for their successful usage in clinical settings, this article also examines present challenges and obstacles in 4D bioprinting technology. Finally, the article also outlines future regulations that will assist researchers in the manufacture of complex products and in the exploration of potential solutions to technological issues
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