Applications in engineering science最新文献

Currently, research on the mechanical properties of corroded steel wire is primarily conducted through corrosion testing, with a lack of in-depth theoretical investigations into the underlying mechanisms. Addressing this research gap, this study employs molecular dynamics (MD) and finite element theory to explore the corrosion process, micro- and macro-mechanical properties of corroded steel wire, and the fracture mechanisms after corrosion. The study achieves a coupling of micro- and macro-scale analyses. Firstly, a molecular dynamics model is established based on the chemical composition of high-strength steel wire, and a novel mixed potential function derived from quantum mechanics is employed to analyze the fracture mechanisms of corroded steel wire. Secondly, a simplified model of randomly corroded pits in steel wire is developed using Python in Abaqus, based on experimental measurements. Finally, the macroscopic fracture process and fracture strength of corroded steel wire are analyzed based on the results from molecular dynamics simulations. These results are then compared to experimental data to validate the accuracy of the theoretical analysis.

This article provides a brief review of research on the impact of anthropogenic increase in atmospheric CO₂ concentration on Earth's climate. A simplified analysis of resonant radiation absorption in gases is conducted. Building upon the material from the cited articles, theoretical and empirical relationships between radiation absorption and the mass of the absorbing material are presented. The concept of saturation mass is introduced. Special attention is given to the phenomenon of thermal radiation absorption saturation in carbon dioxide. By comparing the saturation mass of CO₂ with the quantity of this gas in Earth's atmosphere, and analyzing the results of experiments and measurements, the need for continued and improved experimental work is suggested to ascertain whether additionally emitted carbon dioxide into the atmosphere is indeed a greenhouse gas.

Significance statement

• The impact of anthropogenic increase in atmospheric CO2 concentration on Earth's climate is analysed. • The concept of saturation mass is introduced. • By comparing the saturation mass of CO2 with the quantity of this gas in Earth's atmosphere, and analyzing the results of experiments and measurements, the need for continued and improved experimental work is suggested to ascertain whether additionally emitted carbon dioxide into the atmosphere is indeed a greenhouse gas.

Granular pile is one of the proven soil improvement mechanisms applied especially for reinforcement of compressible soils supporting light structures. The improvement performance of granular piles is influenced by various factors including the dimension parameters (length, spacing and diameter of the piles). The influence of these three dimension parameters on deformation response of reinforced weak soil has widely been reported. However, the most influential parameter affecting deformation of the weak soil has not been clearly identified. Apparently, these dimension parameters do not equally influence the performance of stone columns in lessening soil deformation. Hence, comparative analysis was carried out in the current study to find out the dimension parameter to which deformation of stone column reinforced weak ground is most sensitive. Finite element based parametric numerical analysis was conducted to simulate the weak ground reinforced with a group of granular piles supporting light weight building. For the parametric study, five dimensions for each parameter (diameter, spacing and length) were considered. The dimensions were purposely varied by uniform percentage increase. Field settlement monitoring data was used to track deformation response of the site and validate the finite element results. The numerical analysis reveals that the simulation results have good agreement with the field settlement monitoring data. From sensitivity view point, column spacing was found to be the most controlling and influential parameter affecting deformation of the reinforced weak soil. Similarly, column length is the dimension parameter to which ground deformation is least sensitive.

The main objective of this study is to define the Green functions for four-point boundary value problems. It is a further aim to clarify what properties the Green functions have and to present a method for calculating the elements of these Green functions. The examples are related to two heterogeneous beams with four supports: the (first) [second] beam is (fixed)[pinned] at the endpoints while the intermediate supports are two rollers. Determination of the eigenfrequencies leads to four-point eigenvalue problems associated with homogeneous boundary conditions. Utilizing the Green functions that belong to these eigenvalue problems we can transform those into eigenvalue problems governed by homogeneous Fredholm integral equations. Then a numerical solution is computed by reducing the homogeneous Fredholm integral equations into algebraic eigenvalue problems.

This study investigates the use of BN/ZnO/Al₂O₃/TiO₂ nanoparticles as dopants for Graphene nanoparticles. The sintering process was employed to manufacture semiconductor materials. The bandgap serves as the central feature of an atomic heterojunction, playing a crucial role in determining the characteristics or overall quality of the semiconductor materials involved. X-ray photoelectron spectroscopy (XPS) was employed to ascertain the bandgap values of Boron (B), Nitrogen (N), and Carbon (C) at the interfaces of BN/Graphene, BN/ZnO/Graphene, BN/Al₂O₃/Graphene, and BN/TiO₂/Graphene. The survey spectra were examined to provide evidence of atoms' presence and their respective atomic proportions. The analysis of the narrow spectra of XPS was employed to determine the binding energy of atoms within various materials. The conduction band offset (CBO) and valence band offset (VBO) of the aforementioned heterojunctions were computed. The estimation of the ratio between the conduction band offset (CBO) and the valence band offset (VBO), is denoted as ΔEc/ΔEv,. The significant change in the energy gap in the valance band concerning the change in conduction band energy demonstrates that this material possesses the characteristics of an exemplary semiconductor. The present investigation reveals that the BN/TiO₂/Graphene heterojunction exhibits the highest values of ΔEv/ΔEc, namely 13.07 for nitrogen (N) and 15.07 for boron (B). The results suggest that the combination of BN/TiO₂/Graphene semiconductors holds promising potential for applications in nanoelectronics.

Existing mechano-chemical plants remanufacture waste tires into rubber sheet and recover nylon fibers and metal wires. As a novel expansion of this process to improve its profitability and sustainability, this study proposes the integration of a pyrolysis–distillation system to produce energy products and machinery to produce by-products from the waste steel, such as galvanized wire, nails, and crimped mesh. A quantitative analysis was performed to evaluate the amount of steel wire, energy, and CO₂ emissions saved by the proposed process. Furthermore, the potential profit was calculated at low and high potential scales, representing sustainable national and international development, respectively, with the aim of establishing a circular economy. Twenty-four alternatives based on technical variations were developed and their technical feasibility and potential profit were evaluated and ranked, providing valuable information for decision makers selecting plant layout options. The economic, environmental, and technical feasibility indexes were calculated and used to specify the social feasibility index. Finally, a quadrilateral-bottom-line sustainability development approach was used to calculate the final sustainability index, showing that the proposed integration is indeed a sustainable business approach. The findings of this study prove that there are significant benefits in expanding existing remanufacturing plants to extract value from the many different materials in waste tires.

In this note we study the response of an inhomogeneous body, whose material moduli depend on the density and the mechanical pressure, that is described by an implicit constitutive relation between the Cauchy stress and the right Cauchy–Green tensor. Such a constitutive relation is relevant to the study of the deformation of porous elastic solids as the porous structure varies and the local density changes. The boundary value problems of a plate of such a material subject to uniaxial and bi-axial extension and compression are considered. We find that regions that are more porous, and thus of lower macroscopic density, have the propensity to fail than regions of higher density, in the sense the load carrying capacity decreases, when other measures such as the stress are comparable.

The problem of road-related sinkhole stability has long been one of the main safety concerns to pavement engineers. Collapse and blowout failures are two typical types of pipeline-related sinkhole failures. Although much research on sinkhole stability analyses can be found in the literature, most of them assume a simple circular or rectangular shape of a cavity. In this study, the problem of sinkhole stability in an ellipsoidal cavity is investigated under both blowout and collapse conditions using advanced finite element limit analysis with adaptive meshing in an axisymmetric condition. A dimensionless pressure ratio is defined to represent sinkhole stability that is a function of many design parameters such as depth ratio, elliptical shape ratio, and soil strength ratio. Selected results are compared with published solutions, and comprehensive solutions of the parametric study are presented in the form of charts for use by design engineers. The present study contributes to the understanding of sinkhole stability under an ellipsoidal cavity, and it should be of interest to the road engineering community.

The implementation of 3D laser scanning technology within the architecture, engineering, and construction (AEC) sector possesses the capability to enhance project efficacy and precision. Nevertheless, there exist various obstacles that impede their extensive adoption. This study investigates the key challenges affecting their adoption in the industry. The study employed a mixed-method methodology that involved exploratory factor analysis (EFA) and structural equation modeling (SEM) to examine survey data collected from professionals operating within the architecture, engineering, and construction (AEC) industry. The results reveal significant technical, operational, awareness, and economic challenges. Technical challenges include data processing complexity, limited resources, and compatibility issues. The integration of laser scanning data and perceived risks present operational challenges. Awareness challenges relate to legal factors and change aversion. Economic challenges encompass affordability and time-consuming data acquisition. The ramifications for the industry are significant. Managers should invest in resources, training programs, awareness campaigns, and cost-effective solutions. Future research should expand the sample size and examine long-term effects. Addressing these challenges will enable the AEC industry to fully leverage the potential of 3D laser scanners, enhancing project outcomes and efficiency in the built environment.

Round metal bars are available at various sizes at commercial markets and in industries. These bars are used in various branches of industry, for instance in automobile, aerospace, power and manufacturing engineering as well as paper industry, printing and packaging industry and construction industry. It is often found that round bars as available in open market are not often straight at various sections along the length. As the round bars usually fulfil responsible functions, their surface irregularities should be precisely measured. In the present investigation, straightness of bars is measured section-wise across the length of the bar in order to understand the actual scenario of production quality. An attempt has been made by choosing various different types of materials of different sizes to ascertain the actual availability of bar sizes at commercial market and also to understand the level of straightness of these bars along the axis of the bar. 3D surface plot is also used here to find out whether such bars as commercially available can be utilised for precision industrial applications or not. Finite element analysis is also performed to compare the deformations of different solid round metal bars. Results show that commercially available aluminium bars are showing nearly straight having less deformations compared to bars of other materials.