Application Of Lightweight Materials Research Articles

Effect of Films on In‐Mold Decoration and Microcellular Foaming Injection Molding Parts: Cell Structure, Surface, Warpage, and Mechanical Properties

ABSTRACTThe in‐mold decoration and microcellular foaming injection molding (IMD‐MIM) process was proposed to solve the apparent quality problem of polypropylene in microcellular foaming injection molding. Based on physical experiments and finite element simulation, stainless steel (ST) and polyethylene glycol terephthalate (PET) decorative films were selected for analysis, and the influence of the type and thickness of the decorative films on the cell structure, surface morphology, warpage deformation, and mechanical properties was revealed. The results show that the surface quality of the samples coated is significantly improved, and the asymmetric temperature field caused by the films changes the structure and distribution of the cells. The cell density on the coated side is higher than that on the non‐coated side, and the average cell diameter is smaller, and the foam core layer is shifted to the coated side. The warpage caused by ST film is larger, up to 2.836 mm. With the intervention of ST film and PET film, the impact properties of the samples have little change, but the tensile and flexural properties of the foamed samples have been effectively improved. The tensile strength increased by 28.6% and 25.9%, while the flexural strength increased by 28.6% and 28.1%, respectively. This study provides new insights into the comprehensive optimization of the structure and performance of polypropylene microcellular foaming materials and provides support for the development and application of lightweight materials in the future.

Application of lightweight materials in automobiles: A review

Due to increasing challenges on carbon emissions, there is increased demand for more fuel economic vehicles; weight reduction, an attractive strategy for increasing fuel efficiency, has become prevalent in automobile design. This paper provides a review on weaved carbon fiber composites, long fiber carbon fiber composites, aluminum alloys, magnesium alloys, and glass fiber composites. They are assessed on strength, durability, corrosion resistance, and processing difficulty, to determine whether they can be used in lightweight automobile components. Numerous methods can be used to enhance the mechanical properties and ease of processing of these materials, to make them more appropriate for use. However, the materials all have their specific downsides like high weight, difficulties in processing, low corrosion resistance, or poor fatigue properties. We concluded that the materials are suitable for usage in automotives after undergoing specific Manufacturers should consider the relevance of these advantages and disadvantages to the application of materials in specific parts of the automobile.

Mechanical characterization of FDM printed bio-inspired double arrow head structures

Abstract Biomimetic structures draw their inspiration from nature. Biomimetic structures aim to improve strength, flexibility, and energy efficiency. Safety equipment, aircraft, automotive, and medical equipment incorporate biomimetic structures. In recent days, biomimetic structures were modified by researchers to enhance their mechanical properties. In this study, novel double arrowhead structures were manufactured using material extrusion technology, and the quasi-static compression tests were carried out in the Universal Testing Machine. Finally, the results demonstrated that the highest compressive strength is 13.29 MPa recorded on a modified novel solid square double arrowhead structure. Once more, the solid square double arrowhead structure has more specific strength than every other structure. A greater specific strength indicates that a structure is capable of withstanding greater forces while minimising its weight. In order to provide direction for the practical applications of lightweight materials, this research compares the truss double arrowhead structures with the solid double arrow head structures.

Research on the mechanical clinching process for the metal–polymer multilayer structure

With the wide application of lightweight materials, the metal–polymer multilayer structure has become a research focus owing to the advantages of lower weight and higher vibration damping. In the current work, the mechanical clinching process of the metal–polymer multilayer structure between Al5052-H32 and polyoxymethylene was investigated. The effect of diverse plate configurations and different test specimen forms on the mechanical characteristics was analysed in terms of geometric parameters, static strength, failure modes and energy absorption. The results showed that the metal–polymer multilayer structure could be successfully connected utilizing the mechanical clinching process. The cross-tension load and lap-shear load of the joint were greatly affected by the plate configuration as well as the test specimen form.

3D lightweight double arrow-head plate-lattice auxetic structures with enhanced stiffness and energy absorption performance

In lightweight engineering, higher specific stiffness and strength for low-density are constant quests, additively-manufactured auxetic truss-lattices have attracted great attentions due to their outstanding and designable mechanical properties. Recent advances revealed that the novel family of plate-lattices can enhance the stiffness and energy absorption capacity compared to truss-lattices. In this study, three types of novel 3D double arrow-head plate-lattice (DAPL) auxetic structures are proposed based on the polygon tessellations of 3D double arrow-head truss-lattice (DATL) structures. The compression tests are carried out on 3D printed plate-lattice structures to validate the finite element analysis and the influences of geometrical parameters on elastic constants are also investigated numerically. The results indicate that the 3D DAPL structures present auxetic behavior with enhanced stiffness, and the geometrical tessellation mode has no significant effect on specific stiffness for both 3D DATL and DAPL structures. The quasi-static crushing responses of 3D DAPL and DATL structures are studied and reveal that the plate-lattices can significantly improve the quasi-static energy absorption performances compared with truss-lattices for the same relative density. Finally, the low-velocity impact tests are performed on 3D DAPL structures and the results reveal that 3D DAPL have good impact resistance compared with other lattice structures for low densities. This paper combines the concept of plate-lattice with auxetic mechanism which will provide the guidance for the functional applications of lightweight materials.

Joining of hybrid semi-finished products from sheet metal by orbital forming

Contrary demands like a reduction of carbon dioxide emissions and an increase in functionality are facing the manufacturing industry with growing challenges. When processing functional components, like synchronizer rings, conventional process chains, like shearing and subsequent joining, are reaching their limits due to an increased complexity of the components and a lack in efficiency, referring to the long process time. To meet these challenges, the strategy of lightweight construction combines the application of lightweight materials with efficient manufacturing processes and an innovative product design. One possibility within lightweight construction is the utilization of load-adapted hybrid components, featuring different material strength classes. In previous research, the process of orbital forming is used to manufacture semi-finished products with a varying thickness profile due to the specific radial material flow. This material flow should now be used to realize a permanent joint between materials of two different strength levels. Therefore, the process of orbital forming is modified to manufacture hybrid semi-finished products from a dual-phase steel DP600 and a naturally rigid aluminum alloy EN AW 5754, both with an initial thickness of 2.0 mm. Different joint geometries are cut by laser into a steel ring and the part is coaxially positioned around a basic aluminum disc inside a die and subsequently formed. The joint is investigated regarding the geometrical and mechanical properties, comparing a radial cross-section and the micro hardness distribution. In order to reveal the potential of orbital forming for a combined forming and joining operation, the axial as well as the peeling strength of the multi-material components are investigated and evaluated.

A Review on Lightweight Metal Component Forming and its Application

The present research focused on reviewing forming technology and inspired various method forming processes for different lightweight materials. Nowadays, to improve modern automobiles’ fuel economy while preserving safety and efficiency, advanced materials are essential. Since accelerating a lighter object requires less energy than a heavier one, lightweight materials offer great potential to improve vehicle performance. Innovative forming technologies are discussed concerning each approach and their contribution to lightweight material application. New metal forming methods are implemented to fulfill lightweight material applications in various fields.

Improved Adaptive Augmentation Control for a Flexible Launch Vehicle with Elastic Vibration.

The continuous development of spacecraft with large flexible structures has resulted in an increase in the mass and aspect ratio of launch vehicles, while the wide application of lightweight materials in the aerospace field has increased the flexible modes of launch vehicles. In order to solve the problem of deviation from the nominal control or even destabilization of the system caused by uncertainties such as unknown or unmodelled dynamics, frequency perturbation of the flexible mode, changes in its own parameters, and external environmental disturbances during the flight of such large-scale flexible launch vehicles with simultaneous structural deformation, rigid-elastic coupling and multimodal vibrations, an improved adaptive augmentation control method based on model reference adaption, and spectral damping is proposed in this paper, including a basic PD controller, a reference model, and an adaptive gain adjustment based on spectral damping. The baseline PD controller was used for flight attitude control in the nominal state. In the non-nominal state, the spectral dampers in the adaptive gain adjustment law extracted and processed the high-frequency signal from the tracking error and control-command error between the reference model and the actual system to generate the adaptive gain. The adjustment gain was multiplied by the baseline controller gain to increase/decrease the overall gain of the system to improve the system’s performance and robust stability, so that the system had the ability to return to the nominal state when it was affected by various uncertainties and deviated from the nominal state, or even destabilized.

Optimization of the Vehicles Production by Using Lightweight Carbon Fibre Composite Materials

Through a brief introduction of the current application of lightweight materials in the automotive market, it is proposed that carbon fibre composites are a promising application. Therefore, it is constructive to study the advantages and disadvantages of the application and then put forward suggestions for improvement.

Lightweight Wheel Bearing with Dissimilar Materials for Vehicle

<div class="section abstract"><div class="htmlview paragraph">Limited fossil fuel resources, air pollution, and global warming all drive strengthening of fuel economy and vehicle emission standards globally. Much R&D continues to be dedicated to improve fuel efficiency of automobiles and to reduce exhaust gasses. These include improvement of engine/driveline performance for higher efficiency, development of alternative energy, and minimization of air resistance through aerodynamic design optimization. OEM weight reduction-focused research has extended into chassis components (steering knuckle, brakes, control arms, etc.) in sequence from body-in-white(BIW). Wheel bearings, one of the core components of a driveline and part of a vehicle’s unsprung mass, are also being required to reduce weight. Conventionally, wheel bearings have achieved “lightweighting” primarily through design optimization methods. They have been highly optimized today using steel based materials. Opportunities for further mass optimization are increasingly limited and so the focus of this study is integration of lighter-materials into steel bearing components for weight savings. Both aluminum and CFRP were considered in the study for partial integration into the steel hub flange which interfaces directly with the wheel. The application of lightweight materials was targeted on the specific area of the hub which is relatively less affected by impact loads. Hot forging and compressive molding were applied to induce denser bonding of the dissimilar materials. The slope angle design having an inverse draft at the combined boundary was applied to reinforce physical bonding and to enhance joint integrity. In addition, a Zinc-based coating was partially applied on the surface of the combined boundary to protect against galvanic corrosion between dissimilar materials. Bearings containing the new composite hubs achieved a 20% weight reduction compared to conventional wheel bearings made of full steel.</div></div>

Challenges and Opportunities in Remote Laser Welding of Steel to Aluminium

In the last two decades, the automotive industry has been facing demands to reduce fuel consumption and to meet CO2 emissions through applications of lightweight materials. Therefore, aluminium alloys have replaced substantial amounts of steel; and they are receiving significant attention to achieve greenhouse emission targets. However, a critical factor in applications of advanced aluminium in automotive Body in White (BIW) designs depends on availability of cost effective and high performance joining processes. Currently, a Self-Pierce Riveting (SPR) process is extensively used for aluminium BIW sheet metal parts joining which is expensive, additionally increase the weight of the vehicle and cause inefficiency in manufacturing operations. As aluminium alloys are difficult to weld by conventional technologies such as electrical resistance spot welding, MIG arc welding etc., various joining technologies had proposed to weld aluminium alloys and dissimilar alloys over the years. Often, these technologies restrict design flexibility and are expensive for mass production. In this context, Remote Laser Welding (RLW) has gained popularity because of its distinct advantages such as design flexibility, production speed, material and cost savings. This paper provides a critical review of challenges and opportunities for application of RLW to dissimilar metal welding of steel to aluminium. Next steps of research and development are also highlighted.

Design of composite lattice materials combined with fabrication approaches

Lattice materials can be designed through their microstructure while concurrently considering fabrication feasibility. Here, we propose two types of composite lattice materials with enhanced resistance to buckling: (a) hollow lattice materials fabricated by a newly developed bottom-up assembly technique and the previously developed thermal expansion molding technique and (b) hierarchical lattice materials with foam core sandwich trusses fabricated by interlocking assembly process. The mechanical performance of sandwich structures featuring the two types of lattice cores was tested and analyzed theoretically. For hollow lattice core material, samples from two different fabrication processes were compared and both failed by nodal rupture or debonding. In contrast, hierarchical lattice structures failed by shear buckling without interfacial failure in the sandwich struts. Calculations using established analytical models indicated that the shear strength of hollow lattice cores could be optimized by judicious selection of the thickness of patterned plates. Likewise, the shear strength of hierarchical foam core truss cores could be maximized (with minimal weight) through design of truss geometry. The bottom-up assembly technique could provide a feasible way for mass production of lattice cores, but the design about how to assembly is critical. Hierarchical lattice cores with foam sandwich trusses should be a suitable choice for future lightweight material application.

An analytical study on sliding mode strength at the bonded interface depending on the inclined angle of unidirectional CFRP inclined double cantilever with laminated structure

Background/Objectives: CFRP is getting a great deal of attention with its next-generation lightweight materials. Weight lightening can be greatly improved by designing the structure using the method of bonding lightweight materials.Methods/Statistical analysis: This study was based on BS (British standard) 7991 for mode II (Sliding mode). BS 7991 is a basic research method for identifying the basic elements of CZM (Cohesive zone method). In the mode II as sliding mode of the inclined double cantilever beam, the effects on the materials and the mechanical properties shall be identified when the sliding load working at the bonded interface appears.Findings: Unidirectional CFRP shall be designed in accordance with quasi-isotropic laminate in order for its elastic stiffness to be designed similarly at all the coordination directions. Therefore, the laminate structure used in this study was designed to be [0 / ± 603]s. This is because the adhesion force acting on the bonded interface varies according to the progress of the failure when the interfacial failure occurs in the mode II as sliding mode of the inclined double cantilever. Quasi-isotropic laminate structure has an advantage of not setting differently elastic stiffness depending on the coordination in all the directions. The analysis condition of a restraint has been applied to one of the inclined double cantilevers with remote displacement excluding the rotation direction. The freedom of rotation direction along with forced displacement of sliding direction has been given to remote displacement in the other cantilever. Forced displacement speed was set at 3 mm/min. Given the free direction of rotation in both cantilevers, the inclined double cantilever has been ruptured, minimizing the interference between the elements.Improvements/Applications: In this research, a database for the application of lightweight materials and the bonding method, which are the design elements for lightweight structure, has been constructed.

Static and dynamic analysis of FDM printed lattice structures for sustainable lightweight material application

Static and dynamic analysis of FDM printed lattice structures for sustainable lightweight material application

Static and dynamic analysis of FDM printed lattice structures for sustainable lightweight material application

This study investigated the effect of strut diameter size of fused deposition modelling (FDM) printed lattice structure on compressive performance and its relation to dynamic behaviour of the lattice structure using vibration analysis. The lattice structure samples were fabricated using FDM 3D printing/additive manufacturing (AM) technique with three sizes of strut diameters: 1.2 mm, 1.4 mm and 1.6 mm. Findings from compression test showed that increased in size of strut diameter would increase the compressive strength performance as well as better energy absorptions. Similar increased trend was shown in the vibration analysis as the strut diameter size increased. This study provides information that lattice structure is suitable for use in dynamic load bearing applications.

Application of lightweight materials in structure concept design of large-scale solar energy unmanned aerial vehicle

Carbon fiber composites and film materials can be effectively used in light aircraft structures, especially for solar unmanned aerial vehicles. The use of light materials can reduce the weight of the aircraft, but also can effectively improve the aircraft's strength and stiffness. The structure of the large aspect ratio solar energy UAV was analyzed in detail, taking Solar-impulse solar aircraft as an example. The solar energy UAV has a wing aspect ratio greater than 20, and the detailed digital model of the wing structure including beam, ribs and skin was built, also the Finite Element Method was applied to analyze the static and dynamic performance of the structure. The upper skin of the wing is covered with silicon solar cells, while the lower skin is light and transparent film. The single beam truss form of carbon fiber lightweight material is used in the wing structure. The wing beam is a box beam with rectangular cross sections. The box beam connected the front parts and after parts of the ribs together. The fuselage of the aircraft was built by space truss structure. According to the static and dynamic analysis with Finite Element method, it was found that the aircraft has a small wingtip deflection relative to the wingspan in the level flight state. The first natural frequency of the wing structure is pretty low, which is closed to the gust load.

Theoretical and experimental investigation of deep drawing of tailor-welded IF steel blanks with non-uniform blank holder forces

Tailor-welded blank is one of the promising technologies in the application of lightweight materials for auto body parts manufacturing. The material discontinuity across the weld line results in an inhomogeneous deformation and weld line displacement. In this study, a two-dimensional analytical model is proposed to predict the tension distribution along the cross section. An energy method is used to calculate the restraining force due to bending, sliding, and unbending phenomena on the die and punch radii. To control the weld line movement, a blank holder force control strategy is proposed to achieve force equilibrium at the bottom of the part across the weld line. Finite element simulations are performed to study the effect of die and punch radii, friction coefficient, thickness ratio, and blank holder forces on the weld line displacement in strip drawing process. Under a uniform blank holder force, the weld line moves toward the thicker/stronger side implying a higher blank holder force is required for the thinner/weaker side. The results show that the weld line displacement can be controlled by an appropriate blank holder force adjustment. In order to control the weld line movement in square cup deep drawing, blank holder force on the thinner side is increased and its influences on the deformation process are investigated. Comparisons of material draw-in, weld line movement, and forming force show a good agreement between the theoretical, numerical, and experimental results.

초고장력강과 알루미늄 합금의 판재 접합을 위한 헬리컬 SPR 설계

Self-piercing riveting (SPR) is a sheet-joining method that can be used for materials that are difficult or unsuitable for weld, such as aluminum alloys and other steel sheet metals. The increased application of lightweight materials has initiated many investigations into new SPR conditions for riveting dissimilar materials. However, buckling of the semi-tubular rivet occurs during the riveting of AHSS. In this study, a helical SPR was designed for the riveting of AHSS and Al-alloy. In addition, the reinforced helical SPR which has straight parts was designed. The riveting of AHSS and Al-alloy was simulated. Simulated results were verified by comparison with experimental ones.

A Study on Absorption Energy Characteristic of Hybrid Member for Lightweight Material Application of Vehicle Structural Part

A Study on Absorption Energy Characteristic of Hybrid Member for Lightweight Material Application of Vehicle Structural Part

Heat Transfer Analysis of Light Weight Cryogenic Tank for Space Vehicles

This paper focuses on the application of light weight materials in spherical tank designs for cryogenic tanks. Two cryogenic hydrogen tank design concepts will be considered. This paper is prepared with MatLab and Abacus Version 6.10.1 and the Analysis will include thermal and structural analysis of the tank designs as well as an analysis of hydrogen diffusion to specify the material permeability requirements. Thermal modeling and analysis of a cryogenic tank design exposed to extreme heating profiles, Thermal performance comparison of insulation systems for liquid hydrogen storage tanks, Analysis of cryogenic propellant tank pressurization based upon ground experiments1. A vacuum-jacketed design with an aluminum tank offered the most efficient thermal insulation design option. A tank design with high or low density aerogels results in a much heavier tank system, due to a higher rate of heat penetration and more propellant boil off. As such, aerogels are not a viable insulation option for the storage of cryogenic fuels.