Hasil untuk "Mechanical industries"

Y. Kok, X. Tan, Pan Wang et al.

G. D. Goh, V. Dikshit, A. Nagalingam et al.

M. Hsueh, Chao-Jung Lai, Shi-Hao Wang et al.

Fused Deposition Modeling (FDM) can be used to manufacture any complex geometry and internal structures, and it has been widely applied in many industries, such as the biomedical, manufacturing, aerospace, automobile, industrial, and building industries. The purpose of this research is to characterize the polylactic acid (PLA) and polyethylene terephthalate glycol (PETG) materials of FDM under four loading conditions (tension, compression, bending, and thermal deformation), in order to obtain data regarding different printing temperatures and speeds. The results indicated that PLA and PETG materials exhibit an obvious tensile and compression asymmetry. It was observed that the mechanical properties (tension, compression, and bending) of PLA and PETG are increased at higher printing temperatures, and that the effect of speed on PLA and PETG shows different results. In addition, the mechanical properties of PLA are greater than those of PETG, but the thermal deformation is the opposite. The above results will be a great help for researchers who are working with polymers and FDM technology to achieve sustainability.

Qiong Wu, W. Miao, Yidu Zhang et al.

Abstract As an emerging material, nanomaterials have attracted extensive attention due to their small size, surface effect and quantum tunneling effect, as well as potential applications in traditional materials, medical devices, electronic devices, coatings and other industries. Herein, the influence of nanoparticle selection, production process, grain size, and grain boundary structures on the mechanical properties of nanomaterials is introduced. The current research progress and application range of nano-materials are presented. The unique properties of nano-materials make them superior over traditional materials. Therefore, nanomaterials will have a broader application prospect in the future. Research on nanomaterials is significant for the development and application of materials science.

Shuheng Wang, Yongbin Ma, Z. Deng et al.

Abstract Fused deposition modeling (FDM) is an important process among the available additive manufacturing technologies in various industries. Although there exists many works investigating the effects of FDM process parameters on the mechanical properties of printed materials, there are still several points need to be studied. One is the effects of process parameters on the dynamic mechanical properties of FDM-printed materials, especially in environments where the temperature often changes. The other is the mechanism by which process parameters affect the mechanical properties of printed materials. Aiming at these two points, uniaxial tensile tests and dynamic mechanical analysis are carried out respectively to characterize the tensile properties and dynamic mechanical properties of FDM-printed PLA materials under different FDM process parameters, namely printing angle, layer thickness, fill rate and nozzle temperature. Based on the experimental results explanations are given for the influence of the FDM process parameters on the mechanical properties of the printed materials.

G. Udayakumar, Subbulakshmi Muthusamy, B. Selvaganesh et al.

Abstract Polymers have occupied an indispensable role in almost all types of industries for their immense physical and mechanical characteristics, mainly in food, packaging, pharmaceutical and therapeutic sectors. They were synthesized from chemical monomeric sources which paved the way to become a potentially harmful non-biodegradable waste in the environment. Here comes the introduction of biopolymers, as the organic substances present in natural sources as monomeric units that can be purified and processed based on the desired form of usage. These biopolymers were found to be biocompatible and biodegradable which makes them useful in different applications, such as edible films, emulsions, packaging materials in food industry and as drug transport materials, medical implants like organ, tissue scaffolds, wound healing and dressing materials in pharmaceutical industries. The main focus of this review is to provide a comprehensive knowledge about the physical, thermal, mechanical and optical properties of biopolymers and its composites in relation with the different characterization techniques. A detailed information of its usage in the food and pharmaceutical industries in different forms would be discussed with the upcoming trends thereby providing a wide avenue for enhanced research considering the future demands.

Noshin Tasnim Tuli, Sinthea Khatun, A. Rashid

Rapid advancements in the field of 3D printing in the last several decades have made it possible to produce complex and unique parts with remarkable precision and accuracy. Investigating the use of 3D printing to create various high-performance materials is a relatively new field that is expanding exponentially worldwide. Automobile, biomedical, construction, aerospace, electronics, and metal and alloy industries are among the most prolific users of 3D printing technology. Modern 3D printing technologies, such as polymer matrices that use fiber-reinforced composites (FRCs) to enhance the mechanical qualities of printed components greatly, have been useful to several industries. High stiffness and tensile strength lightweight components are developed from these materials. Fiber-reinforced composites have a wide range of applications, such as military vehicles, fighter aircraft, underwater structures, shelters, and warfare equipment. Fabricating FRCs using fused deposition modeling (FDM) is also advantageous over other 3D printing methods due to its low cost and ease of operation. The impact of different continuous fiber and matrix polymer selections on FRC performance is covered in this review paper. We will also evaluate the important parameters influencing FRC characteristics and review the most recent equipment and methods for fabricating FRCs. Furthermore, the challenges associated with 3D printing fiber-reinforced composites are covered. The constraints of present technology have also been used to identify future research areas.

A. Azarniya, Xabier Garmendia Colera, M. J. Mirzaali et al.

Abstract As one of the most important additive manufacturing (AM) techniques, laser metal deposition (LMD) has been extensively studied specially during the last few years. Similar to other AM techniques, the quality of LMD parts is highly dependent on the processing parameters that need to be optimized so as to obtain geometrically accurate parts as well as favorable microstructures and, thus, mechanical properties. The present review paper therefore aims to present a critical analysis and overview of the relationship between processing parameters, microstructure, and mechanical properties of LMD components made from the Ti–6Al–4V alloy. Moreover, we discuss the applications of LMD parts in the aerospace and biomedical industries as well as the potential of LMD techniques for fabrication of more complex parts such as cellular structures. The paper concludes with a summary of the most important findings and suggestions for future research.

Xue Wang, Liping Zhao, J. Fuh et al.

Additive manufacturing (commonly known as 3D printing) is defined as a family of technologies that deposit and consolidate materials to create a 3D object as opposed to subtractive manufacturing methodologies. Fused deposition modeling (FDM), one of the most popular additive manufacturing techniques, has demonstrated extensive applications in various industries such as medical prosthetics, automotive, and aeronautics. As a thermal process, FDM may introduce internal voids and pores into the fabricated thermoplastics, giving rise to potential reduction on the mechanical properties. This paper aims to investigate the effects of the microscopic pores on the mechanical properties of material fabricated by the FDM process via experiments and micromechanical modeling. More specifically, the three-dimensional microscopic details of the internal pores, such as size, shape, density, and spatial location were quantitatively characterized by X-ray computed tomography (XCT) and, subsequently, experiments were conducted to characterize the mechanical properties of the material. Based on the microscopic details of the pores characterized by XCT, a micromechanical model was proposed to predict the mechanical properties of the material as a function of the porosity (ratio of total volume of the pores over total volume of the material). The prediction results of the mechanical properties were found to be in agreement with the experimental data as well as the existing works. The proposed micromechanical model allows the future designers to predict the elastic properties of the 3D printed material based on the porosity from XCT results. This provides a possibility of saving the experimental cost on destructive testing.

Marc Timmins

Particle accelerators represent some of the most sophisticated engineering achievements of our time. Their construction requires a unique combination of physics insight and mechanical engineering expertise. The aim of this paper is to provide young mechanical engineers with an introduction to the principles, methods, and challenges associated with the mechanical design of accelerators. The lecture upon which this proceeding is based emphasized the translation of functional requirements into engineering specifications, the critical importance of robust and reliable design, and the need for precisely defined drawings supported by international standards such as ISO GPS and GD&T. Through illustrative examples and a practical case inspired by CERN's existing components, the paper underlines the necessity of anticipating lifecycle demands, ensuring manufacturability, and safeguarding operational reliability. Particular emphasis is placed on the contractual value of 2D drawings, the practical application of functional dimensioning, and tolerance chain analysis. By reviewing common pitfalls and exploring best practices, the paper seeks to orient engineers towards design choices that balance cost, reliability, and performance.

Haimo Joehri

This paper gives an overview about aspects of mechanical engineering of undulators. It is based mainly on two types that are used in the SwissFEL facility. The U15 Undulator is an example of an in-vacuum type and the UE38 is an APPLE-X type. It describes the frame, the adjustment of the magnets with flexible keepers and the adjustment of the whole device with eccentric movers.

S. Lee, S. Yoon, In‐Yup Jeon

Although polymers are very important and vastly used materials, their physical properties are limited. Therefore, they are reinforced with fillers to relieve diverse restrictions and expand their application areas. The exceptional properties of graphene make it an interesting material with huge potential for application in various industries and devices. The interfacial interaction between graphene and the polymer matrix improved the uniform graphene dispersion in the polymer matrix, enhancing the general nanocomposite performance. Therefore, graphene functionalization is essential to enhance the interfacial interaction, maintain excellent properties, and obstruct graphene agglomeration. Many studies have reported that graphene/polymer nanocomposites have exceptional properties that enable diverse applications. The use of graphene/polymer nanocomposites is expected to increase sustainably and to transform from a basic to an advanced material to offer optimum solutions to industry and consumers.

Yongjian Sun, Jian Wang, Xiaohong Wang

Nobumitsu Hirai, Yuhei Miwa, Shunta Hattori et al.

Biofilms cause a variety of problems, such as food spoilage, food poisoning, infection, tooth decay, periodontal disease, and metal corrosion, so knowledge on biofilm prevention and removal is important. A detailed observation of the three-dimensional structure of biofilms on the nanoscale is expected to provide insight into this. In this study, we report on the successful in situ nanoscale observations of a marine bacterial biofilm on glass in phosphate buffer solution (PBS) using both scanning ion conductance microscopy (SICM) and confocal laser scanning microscopy (CLSM) over the same area. By observing the same area by SICM and CLSM, we were able to clarify the three-dimensional morphology of the biofilm, the arrangement of bacteria within the biofilm, and the difference in local ion conductivity within the biofilm simultaneously, which could not be achieved by observation using a microscope alone.

E. Blanc‐Betes, N. Gomez‐Casanovas, C. J. Bernacchi et al.

ABSTRACT The expansion of sugarcane onto land currently occupied by improved (IMP) and semi‐native (SN) pastures will reshape the U.S. bioenergy landscape. We combined biometric, ground‐based and eddy covariance methods to investigate the impact of sugarcane expansion across subtropical Florida on the carbon (C) budget over a 3‐year rotation. With 2.3‐ and 5.1‐fold increase in productivity over IMP and SN pastures, sugarcane displayed a C use efficiency (CUE; i.e., fraction of gross C uptake allocated to plant growth) of 0.59, well above that of pastures (0.31–0.23). Sugarcane also had greater C allocation to aboveground productivity and hence, harvestable biomass relative to IMP and SN. Cane heterotrophic respiration over the 3‐year rotation (903 ± 335 gC m−2 year−1) was 1% and 14% higher than IMP and SN pastures, respectively. These soil C losses responded largely to disturbance over the first year after conversion (1510 ± 227 gC m−2 year−1) but declined in subsequent years to an average 599 ± 90 gC m−2 year−1—well below those of IMP (933 ± 140 gC m−2 year−1) and SN (759 ± 114 gC m−2 year−1) pastures—despite a significant 40%–61% increase in soil C inputs. Soil C inputs, however, shifted from root‐dominated in pastures to litter‐dominated in sugarcane, with only 5% C allocation to roots. Reduced decomposition rates in sugarcane were likely driven by changes in the recalcitrance and distribution rather than the size of the newly incorporated soil C pool. As a result, we observed a rapid shift in the net ecosystem C balance (NECB) of sugarcane from a large source immediately following conversion to approaching the net C losses of IMP pastures only 2 years after conversion. The environmental cost of converting pasture to sugarcane underscores the importance of implementing management practices to harness the soil C storage potential of sugarcane in advancing a sustainable bioeconomy in Southeastern United States.

Stanica Nedović, Ana Alil, Sanja Martinović et al.

Specific environmental conditions, such as marine environments, often influence steel applications in marine industries. These conditions are commonly simulated using a NaCl solution to simplify the study and eliminate the complexities of seawater's chemical and biological variability. In this study, 42CrMo4 steel samples, a widely utilized material in components subjected to static and dynamic stresses found in vehicles, engines, and machinery, were selected for analysis due to their susceptibility to various forms of corrosion. The corrosion behavior of the samples was monitored using mass loss and corrosion rate. The results were then correlated with changes in mechanical properties, including tensile strength and Brinell hardness. The study provides insight into how corrosion impacts the degradation of mechanical properties.

Hussein A. Kazem, Miqdam T. Chaichan, Ali H.A. Al-Waeli et al.

Integrating the photovoltaic/thermal (PV/T) system in green hydrogen production is an improvement in sustainable energy technologies. In PV/T systems, solar energy is converted into electricity and thermal energy simultaneously using hot water or air together with electricity. This dual use saves a significant amount of energy and officially fights greenhouse gases. Different cooling techniques have been proposed in the literature for improving the overall performance of the PV/T systems; employing different types of agents including nanofluids and phase change materials. Hydrogen is the lightest and most abundant element in the universe and has later turned into a flexible energy carrier for transportation and other industrial applications. Issues, including the processes of Hydrogen manufacturing, preservation as well as some risks act as barriers. This paper provides an analysis of several recent publications on the efficiency of using PV/T technology in the process of green hydrogen production and indicates the potential for its increased efficiency as compared to conventional systems that rely on fossil fuels. Due to the effective integration of solar energy, the PV/T system can play an important role in the reduction of the levelized cost of hydrogen (LCOH) and hence play an important part in reducing the economic calculations of the decarbonized energy system.

T. A. Ganiev, T. B. Minniakhmetov, S. L. Sabanov et al.

The oil and oil refining industries commonly uses vertical steel tanks for the safe storage of crude oil and petroleum products. However, the operation of these tanks comes with risks such as: corrosion, mechanical damage, and non-uniform deformation can result in significant failures with serious environmental and economic consequences. For this reason, regular monitoring of tank technical state is especially important. Early detection of deviations from design parameters, which is possible thanks to monitoring, can help prevent accidents. This paper examines the use of surface laser scanning technology is a method for inspecting tank walls. This method involves creating a 3D digital model of the tank, analyzing its stress-strain state, and identifying deviations from its original geometry. The use of a 3D scanner ensures high measurement accuracy and automates the data collection process. The study's results indicate that surface laser scanning is an effective tool for detecting deformations in tank walls and for monitoring their progression over time. Compared to traditional visual and dimensional inspection methods, this technology provides a more comprehensive assessment of the technical condition of the tanks. This approach reduces diagnostic costs and improves the safety and reliability of tank operations. The practical value of this study lies in the potential integration of surface laser scanning technology into the routine monitoring system of tank farms. This integration can enhance safety and extend the service life of oil storage facilities.

Dean Chen, Armin Pomeroy, Brandon T. Peterson et al.

Compliant mechanisms have significant potential in precision applications due to their ability to guide motion without contact. However, an inherent vulnerability to fatigue and mechanical failure has hindered the translation of compliant mechanisms to real-world applications. This is particularly challenging in service environments where loading is complex and uncertain, and the cost of failure is high. In such cases, mechanical hard stops are critical to prevent yielding and buckling. Conventional hard-stop designs, which rely on stacking single-DOF limits, must be overly restrictive in multi-DOF space to guarantee safety in the presence of unknown loads. In this study, we present a systematic design synthesis method to guarantee overload protection in compliant mechanisms by integrating coupled multi-DOF motion limits within a single pair of compact hard-stop surfaces. Specifically, we introduce a theoretical and practical framework for optimizing the contact surface geometry to maximize the mechanisms multi-DOF working space while still ensuring that the mechanism remains within its elastic regime. We apply this synthesis method to a case study of a caged-hinge mechanism for orthopaedic implants, and provide numerical and experimental validation that the derived design offers reliable protection against fatigue, yielding, and buckling. This work establishes a foundation for precision hard-stop design in compliant systems operating under uncertain loads, which is a crucial step toward enabling the application of compliant mechanisms in real-world systems.

Bela Schulte Westhoff

Classical Electrodynamics in ponderable media remains defined by a century-long debate over force and energy localization. While the prevailing view treats competing formulations (Minkowski, Abraham, etc.) as equivalent conventions, this monograph argues that global conservation is insufficient for physical validity. A formulation must be mechanically coherent: power transfer must strictly equal the work rate of the force acting on the mass target. We formalize this requirement as the Force--Energy Consistency Criterion (FECC) -- a ``Kinematic Lock'' ($ P = \mathbf{f} \cdot \mathbf{v} $) -- and use it to audit standard macroscopic tensors. The analysis demonstrates that only the Macroscopic Vacuum (Lorentz) Formulation offers a mechanically consistent description of total energy-momentum transfer. The internal distribution of this energy is shown to be macroscopically indeterminate. By reinterpreting spatial averaging as spectral filtering, we reconstruct the theory from the microscopic baseline. This perspective identifies a universal host interface that routes electromagnetic energy into mechanical work, heat, and reversible storage, revealing a structural isomorphism where thermodynamics, mechanics, and electrodynamics emerge as coupled spectral projections.