mechanical field
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Workplace health and safety has been of paramount importance for any nation and the stakeholders- authorities, employers and workers – must have reasonable sensitization for the same. During the COVID 19 pandemic, lots of policy formulations and regulations had to incorporate within the industries for the health and welfare of the workers. The “new normal” will take some time for adjustments, challenges and implications to be implemented effectively and consistently. Certain processes in the workplace, especially in the mechanical engineering companies, are likely for high close contact incidences. Special situations pertaining to workers’’ health, like crowded accommodations, travel risks as well common canteens, all need to be reconsidered for providing safer environment to the workers, as far as the current pandemic is concerned. This requires coordinated efforts from all the stakeholders within the mechanical field through subconscious acceptance of the norms of safety and hygiene at all levels.

Abstract In this paper, we mainly introduce the research status and development trend of welding numerical simulation technology. It is mainly reviewed that the simulation of molten pool flow field, welding temperature field and mechanical field, welding deformation and residual stress, hydrogen diffusion analysis, carbon migration of dissimilar steel welded joints, special welding process, microstructure of welded joints and grain growth process of welding heat affected zone. Then we discuss the special welding process simulation technology and special software for welding simulation. Finally, the development of welding numerical simulation technology in China are concerned.

The local radial basis function collocation method (LRBFCM), a strong-form formulation of the meshless numerical method, is proposed for solving piezoelectric medium problems. The proposed numerical algorithm is based on the local Kansa method using variable shape parameter. We introduce a novel technique for the determination of shape parameter in the LRBFCM, which leads to greater accuracy, and simplicity. The implemented algorithm is first verified with a 2D Poisson equation. Then, we employed LRBFCM in a numerical simulation for 2D and 3D piezoelectric problems involving mutual coupling of the electric field and elastodynamic equations for mechanical field. The presented meshless method is verified using corresponding results obtained from the finite element method and moving least squares meshless local Petrov–Galerkin method. In particular, the 2D piezoelectric problem is verified with an exact solution.

Textile materials are often subjected to different stresses, acting on them in two phases: during the knitting phase, when the yarns and the obtained structure are subjected to cyclic stress, but also during the use phase, when the knitted structures are subjected to various stresses. The dynamic behaviour of knitted fabrics in a vibrating environment is usually evaluated by standardized methods, such as the method using vibration exciters (e.g., ISO 10819:2013). However, in recent years, the authors' collective has carried out research to characterize the behaviour of knitted structures in a vibrating environment, using a well-known method for generating vibrations by impact excitation, which is specific to the mechanical field but also has a high potential for application in the textile field. This method refers to the determination of the free vibrations of an elastic system. Its measurement in the design phase of the system is considered a crucial step, since by knowing the frequency range of the system, the resonance phenomenon in the operational phase can be avoided. Similar results obtained by applying standardized methods for measuring vibration transmissibility and the currently adapted method from the field of mechanics to the field of textiles, represent a validation for this type of investigation process and also show the high potential of knitwear to be used in the vibration environment.

Titanium dioxide (TiO2), owing to its non-toxicity, chemical stability, and low cost, is one of the most valuable ceramic materials. TiO2 derived coatings not only act like a ceramic protective shield for the metallic substrate but also provide cathodic protection to the metals against the corrosive solution under Ultraviolet (UV) illumination. Being biocompatible, TiO2 coatings are widely used as an implant material. The acid treatment of TiO2 promotes the attachment of cells and bone tissue integration with the implant. In this chapter, the applications of TiO2 as a corrosion inhibitor and bioactive material are briefly discussed. The semiconducting nature and high refractive index of TiO2 conferred UV shielding properties, allowing it to absorb or reflect UV rays. Several studies showed that a high ultraviolet protection factor (UPF) was achieved by incorporating TiO2 in the sunscreens (to protect the human skin) and textile fibers (to minimize its photochemical degradation). The rutile phase of TiO2 offers high whiteness, and opacity owing to its tendency to scatter light. These properties enable TiO2 to be used as a pigment a brief review of which is also addressed in this chapter. Since TiO2 exhibits high hardness and fracture toughness, the wear rate of composite is considerably reduced by adding TiO2. On interacting with gases like hydrogen at elevated temperatures, the electrical resistance of TiO2 changes to some different value. The change in resistance can be utilized in detecting various gases that enables TiO2 to be used as a gas sensor for monitoring different gases. This chapter attempts to provide a comprehensive review of applications of TiO2 as an anti-corrosion, wear-resistant material in the mechanical field, a UV absorber, pigment in the optical sector, a bioactive material in the biomedical field, and a gas sensor in the electrical domain.

The main purpose of the paper is to warn the academic environment that neither Romanian universities, nor Romanian business organizations, nor public or social ones sufficiently capitalize on students’ creativity. To begin with, we have presented some links that should be built at the society level between certain notions of creativity management and the goals of sustainable global development. In essence, any step taken by modern organizations towards sustainable development, starting with the development of a recyclable product and ending with the development and implementation of an innovative strategy, involves the maximum use of this inexhaustible resource, which is human creativity and is more pronounced among young people. After this bibliographic study, we have presented the results of a research from secondary sources carried out at the Faculty of Engineering of the “Lucian Blaga” University of Sibiu. We have analysed the team projects made by the students of the final years from the Mechatronics and Economic Engineering in the Mechanical Field specializations to those economic subjects that sought, among other things, to develop their creativity. The research was conducted over the last two academic years. We mention that most of the students had a job, and several of their projects used data from the companies in which they were employed. Although they had the consent of management for using and processing of data, too few organizations showed interest in the results of their scholar research. Whether or not the projects used company data, a very small number of students said that the management of the organization in which they work would be interested in their projects. Our main recommendation is to find ways to bring engineering faculties closer to organizations in the field of production and services.

For in-wheel driving vehicle electric vehicles (EVs), mechanical electromagnetic coupling effect caused by the air gap deformation in permanent magnet synchronous hub motor and intensified by the road excitation deteriorates the EVs performance. In this paper, after studying the numerical method for multi-field coupling problems of hub-driving vehicle under the coupled action of electromagnetic field and mechanical field. The experimental validation is investigated. The results indicate that the multi-field coupling effect in hub-driving motor worsens the dynamics performance of the vehicle. To enhance the vehicle performance, suppress mechanical electromagnetic coupling effect and, at same time, reduce the influence of controllable suspension time delay, a delay-dependent H∞ controller is designed based on Lyapunov theory. By applying the particle swarm optimization (PSO) algorithm and the linear matrix inequality theory, the desired output controller gain is derived. Numerical simulations reflect that the active suspension controller considering control time delay not only achieves the favorable riding comfort performance and restrains the coupling effect in hub driving motor but also ensures the suspension deflection and the safety performance requirement. Moreover, it maintains the closed-loop asymptotically stability regardless of t the variation on the sprung mass and control time delay.

Sheet metal forming process is a basic deformation method in the mechanical field. In particular, bending deformation processing is a universal processing method which is widely used to form sheet metal parts such as aviation industry, shipbuilding, automotive and so on. During sheet metal bending process, the forming force is a very important output parameter that needs to be determined to ensure the load capacity of a machining equipment. This forming force magnitude will vary according to machining conditions, Geometric shapes of products, sheet materials, etc. This study examines the influence of technological and geometric parameters such as: work-piece temperature, punch speed and sheet thickness to bending force when forming V-shape of SS400 sheet material.