Manufacturing A Personalised Composite Material Driver’s Seat

The paper presents the process of 3D-printing and laminating a composite material driver’s seat for Silesian Greenpower’s electric vehicle. Silesian Greenpower is a student’s interfaculty project, of which aim is to design, build and race a small electric race car. Aerodynamics and lightweight construction play a major role, so each element applied in the car is optimized and customized to fit in the vehicle. For this purpose, 3D-printing technology is often used by the team. A seat model made on the basis of the driver's anthropometric model was presented in the paper. Subsequently, after the appropriate adaptation of the obtained surfaces to interconnect them with each other, the FDM technology was applied using PET-G material. To increase the strength of the connections of the printed elements and to strengthen the design and stability of the chair, the element was laminated using carbon fibre and epoxy resin. The lamination process is presented and discussed in the article.

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.

Thermal performance of a novel lightweight emergency construction system in different climates

Prefabricated, lightweight construction systems, thanks to their quicker construction processes, cheapness, higher portability, and adaptability, are increasingly proposed all around the world as emergency architectures (after natural disasters, pandemics, etc.), and as affordable housing solutions in countries with increasing housing demand. Due to their low thermal inertia, however, these buildings are often characterized by poor thermal performance in hot climates due to indoor overheating. The possible application of passive cooling measures is often investigated to improve their thermal performance. Among others, cool materials present some advantages in terms of ease of application and costs. However, few studies investigated the impact of this passive strategy on the thermal performance of emergency buildings. For this reason, this work evaluates the impact of cooling materials on the thermal performance of a novel lightweight prefabricated construction system (HOMEDONE) based on the assembly of reinforced-EPS panels. First, a numerical model of an experimental mock-up was created and calibrated on experimental data. Then, the thermal performance of a typical temporary housing solution was numerically evaluated under different climatic locations. Finally, the effectiveness of cooling finishing materials is investigated. The potential of cooling materials in reducing the energy demand for the studied construction system is then highlighted.

Seismic Analysis of Lightweight and Conventional Buildings: A Comparative Study

In recent decades, the use of light-weight materials over heavy-weight materials has increased at a faster rate. When it comes to cost and resource savings, lightweight construction is considered to be more essential. AAC block is a lightweight construction material that provides good acoustic and thermal insulation. In seismic zones, the use of lightweight materials in building reduces the percentage of damages. The goal of this research is to conduct a project comparison study of seismic analysis of buildings composed of lightweight and conventional materials. RSM creates a structural model of a multi-story structure (G+3) and analyses it in Etabs (Response Spectrum Method). Buildings constructed using infill AAC (Autoclaved aerated concrete) blocks and traditional clay brick masonry are designed for the same seismic hazard in conformity with Indian norms. The buildings' analytical results will be compared. The project also aims to familiarise students with Etabs2016. Keywords: Autoclaved Aerated Concrete, Conventional Brick Replacement, Lightweight Construction, Lightweight Material.

Shear resistance of sandwich panel connection at elevated temperature

PurposeSandwich construction has developed and has become an integral part of lightweight construction. In the recent projects, it has been shown that by using sandwich panels as stabilizing members, a considerable amount of savings of steel can be achieved for structural members at ambient temperature. These stabilizing effects may also help to achieve similar savings in case of fire.Design/methodology/approachThe response of a sandwich single panel as well as the behaviour of the whole structure at ambient temperature and in case of fire is influenced by joints between the sandwich panels and the sub-structure. The fastenings used to fix the sandwich panels to a sub-structure may be loaded by shear forces caused by self-weight, live loads or diaphragm action. Therefore, an experimental investigation was conducted to investigate the shear behaviour of sandwich panel joints in fire.FindingsThis paper summarized briefly the experimental results, numerical simulations and analytical models on the shear behaviour of sandwich panel joints at ambient and elevated temperatures.Research limitations/implicationsThe work is limited to studied types of screws and sandwich panels which are generally used in current sandwich construction.Practical implicationsThese stabilizing effects in sandwich construction help to achieve savings in case of fire.Social implicationsSandwich construction has developed and has become an integral part of lightweight construction. In the recent projects, it has been shown that by using sandwich panels as stabilizing members, a considerable amount of savings of steel can be achieved for structural members at ambient temperature. These stabilizing effects help to achieve similar savings in case of fire.Originality/valueThis paper summarized briefly the experimental results, numerical simulations and analytical models on the shear behaviour of sandwich panel joints at ambient and elevated temperatures, which were not published yet.

The Present State of Surface Conditioning in Cutting and Grinding

All manufacturing processes have an impact on the surface layer state of a component, which in turn significantly determines the properties of parts in service. Although these effects should certainly be exploited, knowledge on the conditioning of the surfaces during the final cutting and abrasive process of metal components is still only extremely limited today. The key challenges in regard comprise the process-oriented acquisition of suitable measurement signals and their use in robust process control with regard to the surface layer conditions. By mastering these challenges, the present demands for sustainability in production on the one hand and the material requirements in terms of lightweight construction strength on the other hand can be successfully met. In this review article completely new surface conditioning approaches are presented, which originate from the Priority Program 2086 of the Deutsche Forschungsgemeinschaft (DFG).

The Plant-Like Structure of Lance Sea Urchin Spines as Biomimetic Concept Generator for Freeze-Casted Structural Graded Ceramics

The spine of the lance sea urchin (Phyllacanthus imperialis) is an unusual plant-akin hierarchical lightweight construction with several gradation features: a basic core–shell structure is modified in terms of porosities, pore orientation and pore size, forming superstructures. Differing local strength and energy consumption features create a biomimetic potential for the construction of porous ceramics with predetermined breaking points and adaptable behavior in compression overload. We present a new detailed structural and failure analysis of those spines and demonstrate that it is possible to include at least a limited number of those features in an abstracted way in ceramics, manufactured by freeze-casting. This possibility is shown to come from a modified mold design and optimized suspensions.