Virtual Work Research Articles

Multi-segmented fifth-order polynomial–shaped shells under hydrostatic pressure

The design and construction of submerged complex shells for new applications in offshore structures are increasingly popular. Therefore, the purpose of this study is to present the analytical model and Lagrange multipliers associated with the constraint equation for large displacement analysis of a fifth-order polynomial–shaped shell under hydrostatic pressure for the first time. The shell geometry can be computed using differential geometry with a fifth-order polynomial. The energy functional of the fifth-order polynomial–shaped shell is derived based on the principle of virtual work and written in the appropriate form. The nonlinear static responses of the fifth-order polynomial–shaped shell under hydrostatic pressure can be calculated using the nonlinear finite element method via the fifth-order polynomial shape function. This study develops the model using one-dimensional beam elements divided along the shell radius. To avoid the slope of a meridian curve at the equatorial plane approaching infinity, the shell is divided into two regions defined by different surface parameters. At the junction of two adjacent regions, the continuity requirements are established as the constraint conditions using Lagrange multipliers. The numerical results from the proposed methods are demonstrated and discussed, along with the effects of varied seawater depth, thickness, and elastic modulus on the deformed configuration and principal curvature at the deformed state. The results show that the nonlinear displacement is higher than the linear one in the case of the hydrostatic pressure, whereas the case of the internal pressure has an opposite result. For principal curvatures at the apex, the principal curvatures increase as the seawater depth increases, whereas the principal curvatures decrease when the thickness and elastic modulus increase.

An Approach of BIM-Based Dynamic Adaptive Zoning for Group Piles Construction Multi-Work Areas

In large-scale pile foundation drilling projects, the absence of digital work area management hampers dynamic construction management, affecting efficiency. This article explores multi-work area management during pile foundation drilling using a BIM parameterized model, focusing on informatization. The results indicate the following: (i) A dynamic zoning method for pile foundation construction using BIM models was developed to support information management systems and address resource allocation challenges amid dynamic construction team changes. (ii) Adaptive zoning methods were proposed, incorporating the dynamic adjustment of construction work areas, including the division of virtual work areas and adaptive adjustment of pile foundation partition parameters. (iii) Work area modeling and zoning were applied on site, with pile foundation modeling aligning with engineering design distribution, and work area zoning accurately reflecting the on-site construction status. (iv) This method enables adaptive synchronization between pile foundation model attributes and work area information, integrating zoning management into the information system to enhance the construction unit’s information management system and digital management level.

Rethinking informal workplace learning in times of complexity

PurposeFast-changing global environment, hybrid and virtual work, today’s workplace is confronted to an unprecedented level of complexity. This conceptual paper aims to explore ways to re-think and adapt informal workplace learning to those recent changes and important dimensions to consider when designing successful learning strategies in the future.Design/methodology/approachTo let emerge interesting tensions and explore new ways to approach informal workplace learning, the authors first look at recent trends in the workplace environment, then go back to some key concepts and ideas from the literature on informal learning. The authors then present two real-life cases they experimented with as scholar-practitioners that demonstrate the importance of a relational learning environment that encompasses virtuality, adaptive challenges and vertical development.FindingsThe new environment calls for new ways to think about informal workplace learning and how to support it. More than ever, organisations should support a culture that promotes collaboration and interactions across areas of expertise, a key condition for finding solutions to complex problems. In this complex environment, where there is no one right solution, organisations will need to rely on leaders who can become role models and show others how to overcome the silo mentality, engage into collaborative reflections, generate alternatives, experiment and learn quickly from what does or does not work.Originality/valueThis study contributes to the literature about workplace learning. It extends the understanding of some benefits that informal workplace learning provides to employees in an attempt to become agile practitioners as the work environment quickly changes and becomes more complex.

Can supervisors dwindle turnover in virtual teams?

Purpose Virtual teams allow companies to recruit the best talents, regardless of their geographic location, which is particularly relevant in the Information and Communications Technology (ICT) sector given the high shortage of qualified human capital. However, the space and time flexibility of these professionals also present other challenges to Human Resource Management, such as work engagement and employee retention. This study aims to assess the extent to which supervisor support can influence work engagement and turnover intention in virtual teams. Design/methodology/approach We use a sample of 420 ICT Portuguese professionals who work in virtual teams to test a conceptual model with partial least squares (PLS). Findings The study results show that supervisor support decreases employee's intention to leave their job. We also found that work engagement mediates the relationship between supervisor support and work engagement. Results show that older employees present higher levels of work engagement and employees with longer tenure perceive less supervisor support. Originality/value This study contributes to elucidate the role played by supervisors in influencing employee engagement and retention in virtual work environments.

On crack simulation by mixed‐dimensional coupling in GFEM with global‐local enrichments

AbstractA strategy that combines the global‐local version of the generalized finite element method (GFEM) with a mixed‐dimensional coupling iterative method is proposed to simulate two‐dimensional crack propagation in structures globally represented by Timoshenko‐frame models. The region of interest called the local problem, where the crack propagates, is represented by a 2D elasticity model, where a fine mesh of plane stress/strain elements and special enrichment functions are used to describe this phenomenon accurately. A model of Timoshenko‐frame elements simulates the overall behavior of the structure. A coarse mesh of plane stress/strain elements provides a bridge between these two representation scales. The mixed‐dimensional coupling method imposes displacement compatibility and stress equilibrium at the interface between the two different element types by an iterative procedure based on the principle of virtual work. After establishing the constraint equations for the interface, the 2D elasticity model is related to the small‐scale model by the global‐local enrichment strategy of GFEM. In such a strategy, the numerical solutions of the local problem subjected to boundary conditions derived from the global‐scale problem enrich the approximation of this same global problem in an iterative procedure. Each step of the crack propagation requires a new sequence of this iterative global‐local procedure. On the other hand, the constraint equation for the interface is defined only once. The crack representation in a confined region by the global‐local strategy avoids a remeshing that would require new constraint equations. Two numerical problems illustrate the proposed strategy and assess the influence of the analysis parameters.

Effects of Matrix Cracking-Induced Delamination on Thermal Buckling of Composite Laminate

Abstract Delamination and matrix cracking are common damage modes in composite laminates, significantly impacting their structural integrity and performance. Under elevated temperatures, the collision of anisotropic thermal expansion and nonlinear stiffness responses affect the onset of thermal buckling in flying vehicles. This study implements a multi-scale analysis framework, incorporating finite element modeling and analytical methods to obtain the reduction in mechanical properties of the composite laminate and its stiffness degradation based on an effective stiffness model due to pre-existing matrix cracking in plies. Based on non-linear equations, obtained from the principle of virtual work, in combination with first-order shear deformable theory and von Kármán strain-displacement relations, the thermal buckling temperature, post-buckling behavior of composite laminates are investigated. This work paves the way for developing a model to predict the influence of the laminate stiffness, delamination size, transverse crack location, stacking sequence, and plies thickness on the laminate.

Applications of augmented reality (AR) in chemical engineering education: Virtual laboratory work demonstration to digital twin development

With advances in information technologies, virtual technologies have become a viable option for chemical engineering educators. Although traditional teaching methods remain effective, they have many limitations when presenting complex phenomena. Virtual technologies like Augmented Reality (AR) have shown great potential as an addition to traditional teaching methods. This study explored the practicality and potential applications of AR technologies in chemical engineering education. In this work, traditional 2D representations of CFD simulation results were replaced by AR experiences to visualise the flow pattern and assist the understanding of the working mechanism behind different devices. Other than CFD result integration, animations were also included in AR experiences for personalised training and inclusive laboratory work experience. AR-assisted training has shown good potential in reducing financial loss and equipment downtime due to improper handling. Besides delivering teaching content, the development process of a digital twin with an AR interface was used to demonstrate how virtual technologies can be involved in digitalisation in Industry 4.0. Beyond the technical contents, important design philosophies were also taught as part of the courses.

Kaizen: A Street Smart Low Latency-Aware Resource Choreography Scheme for Decentralized Autonomous Organization (DAO) and Non-DAO Based Application Execution Over Blockchain and MEC Empowered 6 G Network

Decentralized autonomous organization (DAO)-based applications can revolutionize traditional centralized decision-making procedures and services by enabling scalable, decentralized, autonomous, and democratized decision-making processes. Unlike traditional applications, DAO-based decentralized applications use Ethereum blockchain-based smart contract programs to execute policies or make automated decisions. To that end, 6 G technologies can improve the latency and reliability of many existing blockchain-based DAOs. Previous research did not investigate the execution of DAO and non-DAO-based applications, as well as an adaptive resource choreography scheme, while accounting for various 6 G technologies, blockchain, and mobile-edge cloud (MEC). To prevail over the previous shortcomings, this article supplies a street smart multi-platform coordination, application scheduling, and low-latency-aware resource choreography scheme for both DAO and non-DAO-based application execution over blockchain and MEC-enabled 6 G networks by taking heterogenous DAO and non-DAO application count, application requirements, physical worker, virtual worker, and communication resource status into account. The results verified that the proposed kaizen scheme delivers at least 11.26% app work completion delay gain, 7.2% user energy overhead gain, 6.55% user economic charge gain, and 21% service provider profit than the compared schemes.

Countering technostress in virtual work environments: The role of work-based learning and digital leadership in enhancing employee well-being

Virtual work has been highlighted as an important business trend nowadays. Technostress caused by information and communication technology threatens employee well-being in a virtual context. We integrate insights from the Job Demands-Resources theory to explore the impact of technostress on employee well-being and examine work-based learning and digital leadership capability as buffers of this negative impact via the attenuating effect of work exhaustion. We collected multi-wave survey data from 300 virtual employees to test the theoretical model. Results revealed a significant negative impact of technostress on employee well-being. However, work-based learning and digital leadership capability buffered employees' well-being from this negative effect by reducing their work exhaustion. Our findings extend our understanding of work design and shed light on how to cope with virtual work demands.

Exploring Boundary Violations Among Remote Workers with ICTs

ABSTRACT The global response to the COVID-19 pandemic prompted a widespread shift to remote work, solidifying its status as a prevalent and mainstream employment model. As the world emerges from the health crisis, remote work maintains its popularity. Information and communication technologies (ICTs) played a pivotal role during the pandemic, enabling virtual work from any location at any time. However, the increased reliance on ICTs has elicited both praise and criticism for its potential impact on “work-life balance,” a concept gaining prominence. Notably, the use of instant messaging (IM) and enterprise social networking (ESN) platforms in remote work has become commonplace, raising questions about boundary violations within existing boundary theory research. This study aims to explore the extent of these violations and confirms that the use of IM and ESN tools, in conjunction with job satisfaction, can moderate boundary issues within the boundary theory framework. It contributes valuable insights for optimizing work-life balance and well-being in the context of remote work, thereby benefiting organizations and individuals in the evolving work landscape.

Comparative analysis for optimal placement of piezoelectric actuators on smart thin plate

In contemporary smart structures, piezoelectric ceramic (PZT) actuators serve a crucial structural function. To construct a smart thin plate that integrates structural health monitoring (SHM) and active vibration control objectives, many placement methodologies were discussed. In current research, two positioning strategies of the attached PZT actuators are compared. The first strategy is a well-known controllability concept where PZT actuators’ optimum positions are obtained by maximizing the eigenvalues of the controllability Grammian matrix. The second strategy employs the energy concept to strategically position PZT actuators so that the utmost amount of exerted work is accomplished by the actuators. Thus, the optimal performance of actuators to provide energy for mitigating unwanted vibrations is maintained, as is the optimal excitation required for SHM in the designated modes. Kirchoff’s classical laminate plate theory (CLPT) is used to define displacements as well as the normal strains of this coupled electro-mechanical system, and then, using the Ritz solution, the modal eigenvalue problem is solved, and mode shapes are obtained. Consequently, normal strains are transformed into spatially dependent functions used to define both the virtual work and the controllability of the Grammian matrix for the PZT actuators as a function of their locations. Finally, iterative optimization based on a genetic algorithm (GA) is used to find the optimum actuator locations in the desired modes. The best location for the PZT actuator or actuators is explored for two specimen plates with different boundary conditions. The results for the two studied positioning strategies are then compared, showing the superiority of the proposed energy-based strategy. Further, a quantitative variance-based uncertainty analysis reveals a low variance of the output results for the proposed strategy.

Dynamic model of single-DOF spherical mechanisms based on instantaneous pole axes and Eksergian's equation

Instantaneous pole axes (IPAs) fully describe instantaneous kinematics of spherical mechanisms. In single-degree-of-freedom (single-DOF) mechanisms, IPAs’ locations uniquely depend on the mechanism configuration. Such a property allows the deduction of instantaneous-motion characteristics by means of analytic techniques based on geometric features of the mechanism configuration. Moreover, these geometric/analytic approaches are extendable to mechanism's static analyses since the virtual work principle relates mechanism's statics to its instantaneous kinematics. Analytic approaches based on geometric reasoning are of interest in mechanism design and their further extension to dynamic analyses is appealing in that context. This work proposes a possible extension of IPA-based techniques to dynamic analyses of single-DOF spherical mechanisms by using Eksergian's equation. A novel general dynamic model for single-DOF spherical mechanisms is proposed, which is based on IPAs’ locations. Then, the effectiveness of the proposed model is applied to a relevant single-DOF spherical mechanism.

Application of Virtual Laboratory Work in the Educational Process of the University

The article is devoted to conducting a laboratory workshop in the study of technical disciplines. The purpose of the article is to substantiate the possibility of using virtual laboratory work in a laboratory workshop at a technical university. Methodology. Based on the widespread development of digital technologies and their introduction into the pedagogical process of a technical university, the possibility of using virtual laboratory work is considered. The method of pedagogical experiment was used to check the effectiveness of virtual laboratory work by students of the oil and gas specialty when studying the discipline “Hydroaeromechanics in Drilling”. General requirements for conducting laboratory work on stationary benches and virtually are considered. Didactic principles of conducting laboratory classes using virtual works are noted. The process of developing and designing virtual labs, consisting of three stages, is presented. An analysis of the positive and negative aspects of the use of virtual works is carried out. The experience of conducting virtual work at the Institute of Oil and Gas of the Ufa State Petroleum Technological University is presented. A detailed description of the work “Sedimentation and removal of sludge particles” is given, during which the process of transporting sludge to the day surface is mathematically modeled. Objective difficulties for carrying out laboratory work on stationary stands to demonstrate the process of drilling wells are presented. The advantages of using virtual works to study the drilling process are noted. The positive results of virtual laboratory work are described.

2D4-4 Enhancing Virtual Work Environments: Designing for Optimal Sence of Self-Location

2D4-4 Enhancing Virtual Work Environments: Designing for Optimal Sence of Self-Location

Digital storytelling as virtual work integrated learning: the Mia project in child and family social work education

ABSTRACT Digital Storytelling as a pedagogical tool in higher education is still an emerging technology with great potential for growth and innovation. While there has been a growing interest in the pedagogies of storytelling, its adaptation in digital classrooms is not yet fully realized. This paper reports on a current project developed within the social work program that focuses on applying programmatic approach to assessment and curriculum design using digital storytelling. The project was designed to create safe and supported learning environment for students that encourages the development of practice skills while exploring sensitive topics and issues pertinent to working with children.

A VFM-based identification method for anisotropic thermal-mechanical properties of sheet metals using the digital image correlation and infrared thermography assisted heterogeneous test

The accurate characterization of the anisotropic thermal-mechanical constitutive properties of structural sheet metals at elevated temperatures and under nonuniform stress/strain states is crucial for the precise hot plastic forming and structural behavior evaluation of an engineering sheet part. Traditional thermal-mechanical testing methods rely on the assumption of states homogeneity, leading to a large number of tests required for the characterization of material anisotropy and nonlinearity at various high temperatures. In this work, a highly efficient identification method is proposed that allows the simultaneous characterization of the anisotropic yielding, strain hardening and elasto-plasticity thermal softening material properties using the minimum number of tests, releasing the limitations of traditional identification methods. This is implemented by performing a digital image correlation and infrared thermography assisted heterogeneous high temperature test and processing the full-field measurement data based on the principle of virtual work. A double-notched tensile specimen configuration combined with a center-to-periphery temperature gradient is designed first to enable the high heterogeneity of stress/temperature states. Simulations of the heterogeneous tests are then performed to supply idealized reference data that can be used to evaluate the identification sensitivity of the proposed identification algorithm. After the numerical validation of the methodology, it is then applied to the TC4 titanium alloy sheet specimen using the self-developed experimental setup. The experimental identification results verify that the multiple anisotropic thermal-mechanical elasto-plasticity constitutive parameters can be accurately identified from the heterogeneous test with high computation efficiency, significantly simplifying the testing process in comparison to applying multiple traditional homogeneous tests. The current work provides an effective and convenient alternative to high temperature identification strategies used by the material processing community.

Lateral-distortional buckling of frames composed of non-aligned I-members by a simple distortional beam element considering angling effect

Lateral-distortional buckling may occur in frames composed of non-aligned I-members, for which the buckling resistance may be overestimated if the distortional deformation of the cross-section was ignored. In this regard, the geometric stiffness matrix for a novel straight beam element with nine DOFs per node that incorporates the effect of angling (or concentrated transverse stresses induced by in-plane bending moments) between two non-aligned members via the symmetric and anti-symmetric distortion modes is derived. Specifically, the virtual work done by the induced moments by in-plane bending moments near the angled joints when, in buckling, undergoing the angle of twist and the anti-symmetric distortion, is consistently included in the virtual work formulation. Although the local geometric stiffness matrices appear to be asymmetric, the symmetry of the structural stiffness matrix is ensured in the global assembly process, provided that the compatibility and equilibrium conditions at joints in the deformed configuration are satisfied. The reliability of the present distortional beam element is verified by comparing the present solutions with those by the Abaqus shell element in several well-designed examples, by which the superiority of the present element to the non-distortional beam elements is also demonstrated. Comparison study shows that the effect of distortional deformation is extremely significant when the angled frame is composed of short members, or the arch is of high curvature, and when rigid flanges or flexible webs are adopted. Moreover, the distortional beam element excluding the angling effect will produce significant errors in some particular cases.

Thermo-foldable bending analysis of tunable shells using a higher-order modeling

This article investigates effect of a higher order kinematic modeling on the elasto-static bending results of a shell in double curved form. The graphene origami is introduced in this article as a novel nanofiller with some chemical process to arrive at a controllable material. A copper matrix is used as main constituent reinforced with folded graphene origami. The virtual work principle is used to derive governing equations of the thickness-stretchable shell. After derivation of the governing equations and to arrive at the solution, a class of formulas is used from valid sources for effective material properties of the shell. A verification test is presented before exploring the effect of all main affecting parameters of the graphene origami and ambient on the bending results. The results of this work may be used in the analysis of structures with controllable responses.

Structural performance of steel reinforced concrete L-shaped columns in high temperature

This paper presented structural performance of steel reinforced concrete (SRC) L-shaped columns under high temperature and axial load coupling effects. Considering the influence of the axial load ratio (0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8), eccentricity (25, 50, 75 and 100 mm), concrete strength (40, 50, 60 and 70 MPa), calculation length (500, 1000, 1500 and 2000 mm), the SRC L-shaped columns were tested and analyzed in high temperature conditions. The results demonstrated that: (1) Concrete surface of all specimens was grayish white with many cracks. With the increasing axial load ratio, the number of cracks decreased and crack width increased. (2) The fire resistance decreased by 1.3–15.1 %, 6.1–14.9 %, and 3.8–7.1 % respectively, with increasing axial load ratio, eccentricity, calculation length; the fire resistance increased by 0.7–5.3 % with increasing concrete strength. (3) Axial displacement trend first increased gradually because of the thermal expansion of concrete, and decreased gradually after reaching the maximum axial expansion deformation. With increasing axial load ratio, the maximum axial expansion deformation decreased by 42.4–60.2 %, the time of displacement to reach the maximum expansion deformation decreased by 29.7–57.0 %, and the time of displacement to reach 0 mm decreased by 272.7–366.2 %. Finally, the calculation method for displacement and maximum bearing capacity in high temperature was proposed according to principle of virtual work, which served as a guide for fire evaluation of SRC L-shaped columns.

A peridynamic differential operator modeling approach for ceramic matrix composites microstructure with uniform or non-uniform discretization

Based on the theory of peridynamic differential operator (PDDO), a novel three-dimensional (3D) peridynamic (PD) model for isotropic and orthotropic material is proposed to investigate the elastic mechanical behaviors and stress distribution of Ceramic Matrix Composites (CMC) microstructure. The non-local expressions of strain and stress tensors are derived by employing PDDO and the classical constitutive equations. The bond forces in interface region crossing two different constituent materials are obtained by converting the partial differential terms into the non-local forms. The weak form of PD equations of motion is derived by using the principle of virtual work and PDDO. The validity of this approach is verified by predicting the elastic response and stress distributions of isotropic and orthotropic materials under uniaxial tension and pure shear deformation. Finally, simulations are conducted on a CMC microstructure with fiber and matrix under periodic boundary conditions. It is demonstrated that the current approach can effectively build 3D CMC microstructure with uniform or non-uniform discretization, and accurately predict the stress fields and effective elastic properties.