Advances in design by metallic materials: Synthesis, characterization, simulation and applications

Metals have exerted a significant influence throughout the history of mankind, so much so that the different periods of development have often been marked with the name of some material: bronze age and iron age. And all these centuries are studded with continuous discoveries and improvements that have involved materials. However, perhaps in a fairly recent period something has changed in the relationship between Man and Metals: even if until today the growth of humanity remains substantially based on the full exploitation of metals, their convenience compared to other emerging families of unconventional materials is increasingly questioned. In particular, the central argument for this collection was chosen considering that very recently, a great deal of attention has been paid by researchers and technologists to trying to eliminate metal materials in the design of products and processes in favor of plastics and reinforced composites. After a few years, it is possible to state that metal materials are even more present in our lives and this especially is thanks to their ability to evolve. This Special Issue is focused on that and on the recent evolution of metals and alloys with the scope of presenting the state-of-the-art of solutions where metallic materials have become established, without a doubt, as a successful design solution thanks to their unique properties. The Special Issue also intends to outline the fundamental development trends in the field, together with the most recent advances in the use of the metallic materials

Numerical Assessment of a New Hydro-Pneumatic Suspension System for Motorcycles

This work investigates an innovative hydro-pneumatic suspension system that was recently developed for possibly enhancing the performance of wheeled road vehicles, particularly motorcycles. The device exhibits a highly non-linear behavior, and in particular a strongly regressive spring rate, due to its architecture (featuring a hydropneumatic spring and a coil spring arranged in series). Multibody models are implemented and simulated for a preliminary assessment of its actual benefits and/or drawbacks with respect to common suspension systems. As a starting point of the research, this work focuses on the in-plane dynamics, and in particular on a condition of straight running at constant speed. The load fluctuations on the rear wheel (grip) as well as the velocity of the suspended mass (comfort) under different road inputs at various speeds are analyzed. The numerical results confirm the hydro-pneumatic suspension system as a promising device

Ultra-High-Molecular-Weight Polyethylene Rods as an Effective Design Solution for the Suspensions of a Cruiser-Class Solar Vehicle

Ultra-high-molecular-weight polyethylene (UHMWPE) is a subgroup of the thermoplastic polyethylene characterized by extremely long chains and, as result, in a very tough and resistant material. Due to remarkable specific mechanical properties, its use is gradually being extended to multiple fields of application. This study describes, perhaps for the first time, how the UHMWPE can represent a valid material solution in the design and optimization of suspensions for automotive use, especially in the case of extremely lightweight vehicles, such as solar cars. In particular, in this design study, UHMWPE rods permitted to assure specific kinematic trajectories, functionalities, and overall performance in an exceptionally light suspension systems, developed for an innovative multioccupant solar vehicle. These rods reduced the weight by 88% with respect to the classic design solutions with similar functions, offering, at the same time, high stiffness and accuracy in the movements. An experimental campaign was conducted to evaluate the ratcheting behaviour and other mechanical properties needed for a proper design and use

Using a Total Quality Strategy in a new Practical Approach for Improving the Product Reliability in Automotive Industry

In this paper a Total Quality Management strategy is proposed, refined and used with the aim at improving the quality of large-mass industrial products far beyond the technical specifications demanded at the end-customer level. This approach combines standard and non-standard tools used for Reliability, Availability and Maintainability analysis. The procedure also realizes a stricter correlation between theoretical evaluation methods and experimental evidences as part of a modern integrated method for strengthening quality in design and process. A commercial Intake Manifold, largely spread in the market, is used as test-case for the validation of the methodology. As general additional result, the research underlines the impact of Total Quality Management and its tools on the development of innovation

Use of Sea Waste to Enhance Sustainability in Composite Materials: A Review

The term “sea waste” generally refers to any solid, liquid, or gaseous material or substance that is discarded, disposed of, or abandoned in the ocean, sea, or any other body of salty water, such as a lagoon, etc. This includes waste generated by human activities on land that makes its way into the ocean, as well as waste generated by ships and other vessels at sea. Examples of sea waste include plastic debris, chemicals and toxic substances, oil spills, sewage, and other forms of pollution. These pollutants can harm marine ecosystems, endanger marine life, and impact human health and wellbeing. Efforts are being made by governments, organizations, researchers, and individuals to reduce the amount of sea waste generated, and to clean up existing waste in the ocean. Less attention is usually paid to waste materials of natural origin as they are considered (sometimes wrongly) to be less critical; an example is the tons of organic and inorganic material of natural origin that wash up on the beaches daily and must be landfilled or incinerated. The present paper intends to provide an updated review of research experiences and engineering solutions that are able to offer a second life to natural (biological) sea waste by incorporating it into the creation of new, more sustainable materials, and especially composites

A new method for complexity determination by using fractals and its applications in material surface characteristics

In this article, a new method for complexity determination by using fractals in combination with an artificial intelligent approach is proposed and its application in laser hardening technology is detailed. In particular, nanoindentation tests were applied as a way to investigate the hardness properties of tool steel alloys with respect to both marginal and relevant changes in laser hardening parameters. Specifically, process duration and temperature were considered, together with nanoindentation, later related to surface characteristics by image analysis and Hurst exponent determination. Three different Machine Learning algorithms (Random Forest, Support Vector Machine and k-Nearest Neighbors) were used and predictions compared with measures in terms of mean, variability and linear correlation. Evidences confirmed the general applicability of this method, based on integrating fractals for microstructure analysis and machine learning for their deep understanding, in material science and process engineering

Thermal Behavior of Monocrystalline Silicon Solar Cells: A Numerical and Experimental Investigation on the Module Encapsulation Materials

This research outlines the numerical predictions of the heat distribution in solar cells, accompanied by their empirical validation. Finite element thermal models of five laminated silicon solar photovoltaic cells were firstly established using a simulation software (ANSYS®). The flexible laminated solar cells under study are made of a highly transparent frontsheet, a silicon cell between two encapsulants, and a backsheet. Different combinations of layers (i.e., materials and thicknesses) were taken into account in order to analyze their effect on thermal behavior. Thermal properties of materials were derived in accordance with the literature. Similarly, boundary conditions, loads, and heat losses by reflection and convection were also specified. The solar cells were tested using solar lamps under standard conditions (irradiance: 1000W/m2; room-temperature: 25°C) with real-time temperatures measured by a thermal imager. This analysis offers an interpretation of how temperature evolves through the solar cell and, consequently, how the design choice can influence the cells' efficiency

MACHINE LEARNING TOOLS IN THE ANALYZE OF A BIKE SHARING SYSTEM

Advanced models, based on artificial intelligence and machine learning, are used here to analyze a bike-sharing system. The specific target was to predict the number of rented bikes in the Nova Mesto (Slovenia) public bike share scheme. For this purpose, the topological properties of the transport network were determined and related to the weather conditions. Pajek software was used and the system behavior during a 30-week period was investigated. Open questions were, for instance: how many bikes are shared in different weather conditions? How the network topology impacts the bike sharing system? By providing a reasonable answer to these and similar questions, several accurate ways of modeling the bike sharing system which account for both topological properties and weather conditions, were developed and used for its optimization

INNOVATION IN SOLAR VEHICLES: FROM THE IDEA TO THE PROTOTYPE IN LESS THAN 24 MONTHS

The article aims to describe the integrated path used for the conceptual, functional and constructive design of an exclusive solar vehicle. The project was based on the massive implementation of concurrent engineering and quality tools, rarely used in such an integrated way. New and attractive design, 3D CAD modelling, details design, structural and fluid dynamic validations, in-scale rapid prototyping, functional tests, multi-objective optimization, parts manufacturing and assembly. Thanks to this approach, the solar prototype presents high technological contents, especially in terms of materials, structures and processes, together with their optimizations. Furthermore, large CNC-machined multi-material molds, hybrid manufacturing solutions: everything was used to speed up phases permitting to move from the initial idea to the final prototype in 24 months. Since June 2018, the solar vehicle is on the road, transporting 4 people, weighing less than 300kg, reaching speeds of 120km/h and able to run hundreds of km without fuel