Search results

The purpose of this paper is to investigate a simulation solution for estimating the residual stresses developed in metal fused filament fabrication (MF³) printed parts. Additionally, to verify these estimates, a coupled experimental–computational approach using the crack-compliance method was investigated in this study.

In this study, a previously validated thermomechanical process simulation was used to estimate the residual stresses developed in the MF³ printing process. Metal-filled polymer filament with a solids loading of 59 Vol.% Ti-6Al-4V was studied. For experimental validation of simulation predictions, the MF³ printed green parts were slitted incrementally and the corresponding strains were measured locally using strain gauges. The developed strain was modeled in finite-element-based structural simulations to estimate a compliance matrix that was combined with strain gauge measurements to calculate the residual stresses. Finally, the simulation results were compared with the experimental findings.

The simulation predictions were corroborated by the experimental results. Both results showed the same distribution pattern, that is, tensile stresses at the outer zone and compressive stresses in the interior. In the experiments, the residual stresses varied between 1.02 MPa (tension) and −2.28 MPa (compression), whereas the simulations were predicted between 1.37 MPa (tension) and −1.39 MPa (compression). Overall, there was a good quantitative agreement between the process simulation predictions and the experimental measurements, although there were some discrepancies. It was concluded that the thermomechanical process simulation was able to predict the residual stresses developed in MF³ printed parts. This validation enables the printing process simulation to be used for optimizing the part design and printing parameters to minimize the residual stresses.

The applicability of thermomechanical process simulation to predict residual stresses in MF³ printing is demonstrated. Additionally, a coupled experimental–computational approach using the crack-compliance method was used to experimentally determine residual stresses in the three-dimensional printed part to validate the simulation predictions. Moreover, this paper presents a methodology that can be used to predict and measure residual stresses in other additive manufacturing processes, in general, though MF³ was used as demonstrator in this work.

This paper aims to investigate the feasibility of supportless printing of lattice structures by metal fused filament fabrication (MF³) of Ti-6Al-4V. Additionally, an empirical method was presented for the estimation of extrudate deflection in unsupported regions of lattice cells for different geometric configurations.

Metal-polymer feedstock with a solids-loading of 59 Vol.% compounded and extruded into a filament was used for three-dimensional printing of lattice structures. A unit cell was used as a starting point, which was then extended to multi-stacked lattice structures. Feasible MF³ processing conditions were identified to fabricate defect-free lattice structures. The effects of lattice geometry parameters on part deflection and relative density were investigated at the unit cell level. Computational simulations were used to predict the part quality and results were verified by experimental printing. Finally, using the identified processing and geometry parameters, multi-stacked lattice structures were successfully printed and sintered.

Lattice geometry required considerable changes in MF³ printing parameters as compared to printing bulk parts. Lattice cell dimensions showed a considerable effect on dimensional variations and relative density due to varying aspect ratios. The experimental printing of lattice showed large deflection/sagging in unsupported regions due to gravity, whereas simulation was unable to estimate such deflection. Hence, an analytical model was presented to estimate extrudate deflections and verified with experimental results. Lack of diffusion between beads was observed in the bottom facing surface of unsupported geometry of sintered unit cells as an effect of extrudate sagging in the green part stage. This study proves that MF³ can fabricate fully dense Ti-6Al-4V lattice structures that appear to be a promising candidate for applications where mechanical performance, light-weighting and design customization are required.

Supportless printing of lattice structures having tiny cross-sectional areas and unsupported geometries is highly challenging for an extrusion-based additive manufacturing (AM) process. This study investigated the AM of Ti-6Al-4V supportless lattice structures using the MF³ process for the first time.

This research aims to investigate the impact of fear and perceived knowledge (PK) of Covid-19 on the sustainable consumption behaviour (SCB) of Muslim consumers and to test the mediating role of (intrinsic) religiosity.

A total of 417 responses were collected during Covid-19 lockdown through an online structured survey using the snowball technique. A two-step research approach was adopted. In Study 1, an exploratory factor analysis was performed on the SCB measurement scale through SPSS. In Study 2, hypothesised associations were analysed using SmartPLS-SEM.

PK of Covid-19 pandemic directly motivates SCB in Muslim consumers, whereas fear has no direct effect on any factor of SCB. Religiosity is found to be a significant driver of SCB. Indirect effects also depict that religiosity positively mediates the association between fear and SCB as well as PK and SCB.

The study may guide policymakers and marketers in using the current pandemic as a tool to inspire sustainable consumption. Religious values, teachings and knowledge about the pandemics can be publicised to create awareness and induce desired behaviour to cope with adverse events and adopt sustainable consumption patterns and lifestyles among Muslim consumers.

The article is the pioneer of its kind to present survey research about Covid-19 fear and PK’s impact on SCB through religiosity. It adds to the Islamic marketing literature about religiosity, coping theory, PK and fear of pandemics and their role in transitioning Muslim consumers towards SCB. Moreover, the use of partial least squares structural equation modelling in the context of Covid-19 research was extended.

This paper aims to explore the extent of corporate social responsibility disclosure (hereafter CSRD) in Jordan and also examine whether ownership structure, board of directors and audit committee characteristics influence CSRD.

The extent of CSRD is measured by constructing a CSRD index for industrial firms listed on the Amman Stock Exchange from 2016 to 2021. Panel regression analysis is used to examine the potential effect of ownership structure, board of directors and audit committee on the level of CSRD.

This study provides empirical evidence that diverse groups of shareholders have different effects on CSR engagement, and board characteristics (board size, board independence and gender diversity) play a vital role in increasing voluntary disclosure, including CSR information. There is no evidence to support that CSRD is influenced by audit committee characteristics.

This study recommends that corporate regulators and policymakers can improve CSRD practices by expanding the scope of existing disclosure requirements related to CSR and developing a structured CSRD index to measure the degree of CSRD practices for comparative purposes. Encourage firms to actively participate in social responsibility programs by granting tax incentives and government facilities to firms with the best CSR reports. Policymakers should introduce initiatives that support female’s representation on board. Finally, firms should restructure their boards by increasing board size and the percentage of independent directors to enhance their effectiveness to support CSRD.

This paper contributes further insights into the literature on CSRD practices and disclosure by analyzing data from developing market contexts.

This study aims to investigate the impact of trust in the metaverse on the Islamic banking sector, particularly in facilitating market success. Additionally, it seeks to explore the relationship between metaverse-driven brand image, product features, service quality and overall performance in the market.

Data were collected from 187 participants in Jordan, with the SmartPLS software used to test the hypotheses.

The findings reveal a significant impact of metaverse-enhanced brand image, product features and service quality on Islamic banking market performance. Furthermore, customer trust in the metaverse plays a significant role in shaping the relationship between product features, service quality and Islamic banking market performance.

The study’s practical implications still suggest the need for a more holistic metaverse-driven approach. Investing in service quality initiatives alone may not adequately build and sustain customer trust in the metaverse. Instead, transparent communication on ethical practices in the metaverse is required to reinforce trust and magnify the positive influence of superior service quality in the metaverse.

This paper aims to compare and contrast the concept of conventional futures contract from the Islamic law of contract perspectives. The underlying theory and practice of Islamic finance is based on the principles of Islamic law of contract. Although the necessity of derivative instruments such as the case with futures contract is essential for developments in Islamic finance, the permissibility of using these instruments still remains a debatable issue.

The paper discusses arguments for and against using derivative instruments as in futures, for example, in light with the Qur’an and Sunnah (the Prophet’s traditions), as well as the views of classical scholars, jurists and contemporary researchers. Arguments for and against are analysed systematically to derive a logical conclusion.

The study finds that majority scholars consider futures contracts as non-compliant with the Islamic law due to the fact that selling something that does not exist, deferment in the both counter values, gharar or ambiguity and excessive risk taking, pure speculation and sale of one debt for another.

The study focuses narrowly on conventional futures contract. Analysing other financial derivative contracts could be a future research endeavour.

The study has so far found the verdict of impermissibility of conventional futures contract in its current form as has been argued by majority scholars in the premise that they do not comply with the Islamic law. Policymakers and industry practitioners need to take this opinion of majority scholars while developing new Islamic financial derivatives.

To the best of the author's knowledge, the present research is the first attempt so far that explained the validity of conventional futures by analysing arguments of classical and contemporary jurists, scholars and researchers.