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This study aims to assess the robustness and accuracy of the face-centred finite volume (FCFV) method for the simulation of compressible laminar flows in different regimes, using numerical benchmarks.

The work presents a detailed comparison with reference solutions published in the literature –when available– and numerical results computed using a commercial cell-centred finite volume software.

The FCFV scheme provides first-order accurate approximations of the viscous stress tensor and the heat flux, insensitively to cell distortion or stretching. The strategy demonstrates its efficiency in inviscid and viscous flows, for a wide range of Mach numbers, also in the incompressible limit. In purely inviscid flows, non-oscillatory approximations are obtained in the presence of shock waves. In the incompressible limit, accurate solutions are computed without pressure correction algorithms. The method shows its superior performance for viscous high Mach number flows, achieving physically admissible solutions without carbuncle effect and predictions of quantities of interest with errors below 5%.

The FCFV method accurately evaluates, for a wide range of compressible laminar flows, quantities of engineering interest, such as drag, lift and heat transfer coefficients, on unstructured meshes featuring distorted and highly stretched cells, with an aspect ratio up to ten thousand. The method is suitable to simulate industrial flows on complex geometries, relaxing the requirements on mesh quality introduced by existing finite volume solvers and alleviating the need for time-consuming manual procedures for mesh generation to be performed by specialised technicians.

The use of waste polyethylene terephthalate (PET) plastics derived from shredded bottles in concrete is not formalized yet, especially in reinforced members such as beams and columns. The disposal of plastic wastes in concrete is a viable alternative to manage those wastes while minimizing the environmental impacts associated to recycling, carbon dioxide emissions and energy consumption.

This paper evaluates the suitability of 2D deterministic and stochastic finite element (FE) modeling to predict the shear strength behavior of reinforced concrete (RC) beams without stirrups. Different concrete mixtures prepared with 1.5%–4.5% PET additions, by volume, are investigated.

Test results showed that the deterministic and stochastic FE approaches are accurate to assess the maximum load of RC beams at failure and corresponding midspan deflection. However, the crack patterns observed experimentally during the different stages of loading can only be reproduced using the stochastic FE approach. This later method accounts for the concrete heterogeneity due to PET additions, allowing a statistical simulation of the effect of mechanical properties (i.e. compressive strength, tensile strength and Young’s modulus) on the output FE parameters.

Data presented in this paper can be of interest to civil and structural engineers, aiming to predict the failure mechanisms of RC beams containing plastic wastes, while minimizing the experimental time and resources needed to estimate the variability effect of concrete properties on the performance of such structures.

This study presents finite element (FE) and generalized regression neural network (GRNN) approaches for modeling multiple crack growth problems and predicting crack-growth directions under the influence of multiple crack parameters.

To determine the crack-growth direction in aluminum specimens, multiple crack parameters representing some degree of crack propagation complexity, including crack length, inclination angle, offset and distance, were examined. FE method models were developed for multiple crack growth simulations. To capture the complex relationships among multiple crack-growth variables, GRNN models were developed as nonlinear regression models. Six input variables and one output variable comprising 65 training and 20 test datasets were established.

The FE model could conveniently simulate the crack-growth directions. However, several multiple crack parameters could affect the simulation accuracy. The GRNN offers a reliable method for modeling the growth of multiple cracks. Using 76% of the total dataset, the NN model attained an R2 value of 0.985.

The models are presented for static multiple crack growth problems. No material anisotropy is observed.

In practical crack-growth analyses, the NN approach provides significant benefits and savings.

The proposed GRNN model is simple to develop and accurate. Its performance was superior to that of other NN models. This model is also suitable for modeling multiple crack growths with arbitrary geometries. The proposed GRNN model demonstrates its prediction capability with a simpler learning process, thus producing efficient multiple crack growth predictions and assessments.

The purpose of this study is to investigate the post-buckling analysis of functionally graded columns by using three analytical, approximate and numerical methods. A pre-defined function as an initial assumption for the post-buckling path is introduced to solve the differential equation. The finite difference method is used to approximate the lateral deflection of the column based on the differential equation. Moreover, the finite element method is used to derive the tangent stiffness matrix of the column.

The non-linear buckling analysis of functionally graded materials is carried out by using three analytical, finite difference and finite element methods. The elastic deformation and Euler-Bernoulli beam theory are considered to establish the constitutive and kinematics relations, respectively. The governing differential equation of the post-buckling problem is derived through the energy method and the calculus variation.

An incremental iterative solution and the perturbation of the displacement vector at the critical buckling point are performed to determine the post-buckling path. The convergence of the finite element results and the effects of geometric and material characteristics on the post-buckling path are investigated.

The key point of the research is to compare three methods and to detect error sources by considering the derivation process of relations. This comparison shows that a non-incremental solution in the analytical and finite difference methods and an initial assumption in the analytical method lead to an error in results. However, the post-buckling path in the finite element method is traced by the updated tangent stiffness matrix in each load step without any initial limitation.

This study implements the fourth-order phase field method (PFM) for modeling fracture in brittle materials. The weak form of the fourth-order PFM requires C¹ basis functions for the crack evolution scalar field in a finite element framework. To address this, non-Sibsonian type shape functions that are nonpolynomial types based on distance measures, are used in the context of natural neighbor shape functions. The capability and efficiency of this method are studied for modeling cracks.

The weak form of the fourth-order PFM is derived from two governing equations for finite element modeling. C⁰ non-Sibsonian shape functions are derived using distance measures on a generalized quad element. Then these shape functions are degree elevated with Bernstein-Bezier (BB) patch to get higher-order continuity (C¹) in the shape function. The quad element is divided into several background triangular elements to apply the Gauss-quadrature rule for numerical integration. Both fourth-order and second-order PFMs are implemented in a finite element framework. The efficiency of the interpolation function is studied in terms of convergence and accuracy for capturing crack topology in the fourth-order PFM.

It is observed that fourth-order PFM has higher accuracy and convergence than second-order PFM using non-Sibsonian type interpolants. The former predicts higher failure loads and failure displacements compared to the second-order model due to the addition of higher-order terms in the energy equation. The fracture pattern is realistic when only the tensile part of the strain energy is taken for fracture evolution. The fracture pattern is also observed in the compressive region when both tensile and compressive energy for crack evolution are taken into account, which is unrealistic. Length scale has a certain specific effect on the failure load of the specimen.

Fourth-order PFM is implemented using C¹ non-Sibsonian type of shape functions. The derivation and implementation are carried out for both the second-order and fourth-order PFM. The length scale effect on both models is shown. The better accuracy and convergence rate of the fourth-order PFM over second-order PFM are studied using the current approach. The critical difference between the isotropic phase field and the hybrid phase field approach is also presented to showcase the importance of strain energy decomposition in PFM.

To understand how organizations, public or private, must increase their productivity perception (PP), independently of the sector. This article aims to analyze PP in the digital transformation (DT) process to determine how it is affected by technostress (TS) and work engagement (WE), two concepts that seem to be forces opposing PP.

The authors use data from a questionnaire addressed to personnel in two organizations (public and private). The analysis applies partial least squares technique to the 505 valid responses obtained from these organizations. This analysis is based not on representativeness but on uniqueness.

The results suggest a positive, significant relationship between DT and PP. This article integrates DT and its effects on aspects of people's health, PP and WE. The model thus includes interactions of technology with human elements. In both business and administrative environments, PP is key to optimizing resources and survival of organizations.

DT processes are different and complex because every organization is different. The authors recommend expanding this study to other sectors in both spheres, public and private. Aligning the objectives of the institutions for aid with DT is also quite complicated.

This study contributes to improving participating organizations. It also provides government institutions with a clear foundation from which to encourage actions that promote the health and WE of their workforce without reducing productivity. In addition, this study adds novelty to the research line.

The authors have deepened this line of research by developing fuller knowledge of the relationships among novel and necessary variables in organizations. The authors provide complementary, different and inspiring value in addressing this line of research.

This study aims to adapt and validate the need satisfaction and frustration scale (NSFS) for the Brazilian gig work context and investigate the distinctiveness of the constructs of basic needs satisfaction and frustration among Brazilian gig workers.

Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were conducted on a sample of 351 Brazilian gig workers.

Results from EFA supported a three-factor structure, while results from CFA psychometrically supported a six-factor correlated model. The items that constitute the NSFS presented good discriminant validity (heterotrait-monotrait ratio) and internal consistency (Cronbach’s alpha and McDonald’s omega coefficients). Results regarding criterion validity partially support previous empirical evidence that considers needs satisfaction and frustration independent in relation to well-being and ill-being while reinforcing the need for further investigations. The Brazilian version of the NSFS is shown to be an instrument with robust psychometric qualities to assess workers’ perception of basic needs satisfaction and frustration in Brazilian gig work context.

This study broadens the scope of research on basic psychological needs by introducing a valid and reliable instrument to assess workers’ perceptions of needs satisfaction and frustration in the Brazilian gig work context, a population that has been neglected in self-determination theory research.

O presente estudo teve como objetivos (1) adaptar e validar a Need Satisfaction and Frustration Scale para o contexto brasileiro de gig work e (2) investigar a distinção dos construtos de satisfação e frustração das necessidades básicas entre os trabalhadores gig brasileiros.

A análise fatorial exploratória (AFE) e a análise fatorial confirmatória (AFC) foram realizadas em uma amostra de 351 trabalhadores gig brasileiros.

Os resultados da EFA apoiaram uma estrutura de três fatores, enquanto os resultados da AFC apoiaram psicometricamente um modelo correlacionado de seis fatores. Os itens que constituem a NSFS apresentaram boa validade discriminante (razão heterotraço-monotraço) e consistência interna (coeficientes alfa de Cronbach e ômega de McDonald). Os resultados relativos à validade de critério apoiam parcialmente as evidências empíricas anteriores que consideram a satisfação e frustração das necessidades independentes em relação ao bem-estar e mal-estar, reforçando a necessidade de mais investigações. A versão brasileira da Need Satisfaction and Frustration Scale mostra-se um instrumento com qualidades psicométricas robustas para avaliar a percepção dos trabalhadores quanto à satisfação e frustração das necessidades básicas no contexto brasileiro de trabalho gig.

Este estudo amplia o escopo da pesquisa sobre necessidades psicológicas básicas ao introduzir um instrumento válido e confiável para avaliar as percepções de satisfação e frustração das necessidades dos trabalhadores no contexto brasileiro de gig work, uma população que tem sido negligenciada nas pesquisas da teoria da autodeterminação.

el presente estudio tuvo como objetivos (1) adaptar y validar la Escala de frustración y satisfacción de necesidades para el contexto del trabajo gig brasileño, y (2) investigar el carácter distintivo de los constructos de satisfacción y frustración de necesidades básicas entre los trabajadores gig brasileños.

se realizaron análisis factoriales exploratorios (AFE) y análisis factoriales confirmatorios (CFA) en una muestra de 351 trabajadores gig brasileños.

los resultados de EFA respaldaron una estructura de tres factores, mientras que los resultados de CFA respaldaron psicométricamente un modelo correlacionado de seis factores. Los ítems que componen la NSFS presentaron buena validez discriminante (relación heterorrasgo-monorrasgo) y consistencia interna (coeficientes alfa de Cronbach y omega de McDonald). Los resultados con respecto a la validez de criterio apoyan parcialmente la evidencia empírica previa que considera la satisfacción y la frustración de necesidades independientes en relación con el bienestar y el malestar, al tiempo que refuerzan la necesidad de más investigaciones. La versión brasileña de la Escala de Satisfacción de Necesidades y Frustración se muestra como un instrumento con sólidas cualidades psicométricas para evaluar la percepción de los trabajadores sobre la satisfacción de las necesidades básicas y la frustración en el contexto del trabajo gig brasileño.

este estudio amplía el alcance de la investigación sobre las necesidades psicológicas básicas al presentar un instrumento válido y confiable para evaluar las percepciones de los trabajadores sobre la satisfacción y la frustración de las necesidades en el contexto del trabajo gig brasileño, una población que ha sido descuidada en la investigación de teoría de la autodeterminación.

This paper aims to examine the effect of high-involvement work systems (HIWSs) on completing work and avoiding distraction as two dimensions of presenteeism. It also investigates competence as a mediator of the effect of HIWS on presenteeism.

Data were collected from 343 Bangladeshi bank employees using an online survey. The partial least squares-structural equation modelling (PLS-SEM) was employed to assess the abovementioned linkages.

The findings demonstrate HIWS directly avoid distraction but do not significantly impact the completing work dimension of presenteeism. The findings also indicate that competence mediates the effect of HIWS on completing work but not on avoiding distraction.

Drawing on the job demands-resources (JD-R) model, this study empirically demonstrates the contrasting role of HIWS in completing work and avoiding distraction related to presenteeism. It also provides a novel perspective on the unexplored mediating mechanism of competence on the relationship between HIWS and presenteeism and offers new directions for HIWS and presenteeism research.

Taking job demand-resource (JD-R) and self-determination perspective, the current study focused to see how basic need satisfaction (BNS) – as a personal demand – impacts work engagement directly and indirectly through personal resource (i.e. self-efficacy). Moreover, the aim was to test the dimension-wise impact of BNS, i.e. the need for autonomy, need for belongingness and need for competence in the aforementioned relationship.

This research is a time-lagged survey in which three-wave data of 398 white-collar employees were collected from the service and manufacturing sector of Pakistan through convenience sampling. Each wave of data collection was two months apart. The matched responses yielded an overall response rate of 66.33%. The collected responses were duly analysed using partial least squares structural equation modeling (PLS-SEM).

Results of the study confirmed all direct and indirect hypotheses encompassing the impact of the combined BNS construct on work engagement via self-efficacy. Nonetheless, in the dimension-wise analysis, the indirect impact of the need for job autonomy on work engagement was not validated. This depicted that the need for competence and relatedness are more important predictors of work engagement through the self-efficacy path.

It has been observed that prior research on work engagement was mainly focused on the role of job demands (JDs) and personal resources; however, the role of personal demands along with personal resources has little been discussed. The authors tested the total as well as the specific impact of each component of basic need on work engagement making it possible to examine the total predicting role of basic need satisfaction and the specific contribution of satisfaction of each need on work engagement.