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Article
Publication date: 30 August 2021

Iman Sedighi, Majid R. Ayatollahi, Bahador Bahrami, Marco A. Pérez-Martínez and Andrés A. Garcia-Granada

The purpose of this paper is to study the Mode I fracture behavior of polycarbonate (PC) parts produced using fused deposition modeling (FDM). The focus of this study is…

Abstract

Purpose

The purpose of this paper is to study the Mode I fracture behavior of polycarbonate (PC) parts produced using fused deposition modeling (FDM). The focus of this study is on samples printed along the out-of-plane direction with different raster angles.

Design/methodology/approach

Tensile and Mode I fracture tests were conducted. Semi-circular bend specimens were used for the fracture tests, which were printed in four different raster patterns of (0/90), (15/−75) (30/−60) and (45/−45). Moreover, the finite element method (FEM) was used to determine the applicability of linear elastic fracture mechanics (LEFM) for the printed PC parts. The fracture toughness results, as well as the fracture path and the fracture surfaces, were studied to describe the fracture behavior of the samples.

Findings

Finite element results confirm that the use of LEFM is allowed for the tested PC samples. The fracture toughness results show that changing the direction of the printed rasters can have an effect of up to 50% on the fracture toughness of the printed parts, with the (+45/−45) and (0/90) orientations having the highest and lowest resistance to crack propagation, respectively. Moreover, except for the (0/90) orientation, the other samples have higher crack resistance compared to the bulk material. The fracture toughness of the tested PC depends more on the toughness of the printed sample, rather than its tensile strength.

Originality/value

The toughness and the energy absorption capability of the printed samples (with different raster patterns) were identified as the main properties affecting the fracture toughness of the AM PC parts. Because the fracture resistance of almost all the samples was higher than that of the base material, it is evident that by choosing the right raster patterns for 3D-printed parts, very high resistance to crack growth may be obtained. Also, using FEM and comparing the size of the plastic zones, it was concluded that, although the tensile curves show nonlinearity, LEFM is still applicable for the printed parts.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 25 September 2019

Iman Sedighi, Majid R. Ayatollahi, Bahador Bahrami, Marco A. Pérez-Martínez and Andres A. Garcia-Granada

The purpose of this paper is to investigate the effect of layer orientation on the tensile, flexural and fracture behavior of additively manufactured (AM) polycarbonate…

Abstract

Purpose

The purpose of this paper is to investigate the effect of layer orientation on the tensile, flexural and fracture behavior of additively manufactured (AM) polycarbonate (PC) produced using fused deposition modeling (FDM).

Design/methodology/approach

An experimental approach is undertaken and a total number of 48 tests are conducted. Two types of tensile specimens are used and their mechanical behavior and fracture surfaces are studied. Also, circular parts with different layer orientations are printed and two semi-circular bending (SCB) samples are extracted from each part. Finally, the results of samples with different build directions are compared to one another to better understand the mechanical behavior of additively manufactured PC.

Findings

The results demonstrate anisotropy in the tensile, flexural and fracture behavior of the additively manufactured PC parts with the latter being less anisotropic compared to the first two. It is also demonstrated that the anisotropy of the elastic modulus is small and can be neglected. Tensile strength ranges from 40 MPa to 53 MPa. At the end, mode I fracture toughness prediction curves are provided for different directions of the FDM samples. Fracture toughness ranges from 1.93 to 2.37 MPa.mm1/2.

Originality/value

The SCB specimen, a very suitable geometry for characterizing anisotropic materials, was used to characterize FDM parts for the first time. Also, the fracture properties of the AM PC have not been studied by the researchers in the past. Therefore, fracture toughness prediction curves are presented for this anisotropic material. These curves can be very suitable for designing parts that are going to be produced by 3D printing. Moreover, the effect of the area to perimeter ratio on the tensile properties of the printed parts is investigated.

Details

Rapid Prototyping Journal, vol. 26 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 27 May 2021

Hakan Kalkavan, Hasan Dinçer and Serhat Yüksel

Economic development is one of the primary goals of all countries. In this context, countries aim to determine effective and correct policies to achieve this goal. This…

Abstract

Purpose

Economic development is one of the primary goals of all countries. In this context, countries aim to determine effective and correct policies to achieve this goal. This situation is especially important for developing countries. These countries aim to grow their economies to reach the level of developed countries. This study aims to identify significant Islamic moral principles for sustainable economic growth of emerging seven (E7) countries.

Design/methodology/approach

In this framework, eight different criteria are defined to improve the welfare in the society for these countries. Additionally, fuzzy decision-making trial and evaluation laboratory (DEMATEL) approach is taken into consideration in the analysis process.

Findings

It is identified that Islamic moral values in economic activities, fair income distribution and taxation and prohibition of interest and securing business partnership are the most significant criteria. On the other side, it is found that preventing poverty and avoiding wastage are the influenced factors.

Practical implications

The findings show that righteousness in commercial activities decreases uncertainty in the market so that trade volume can be increased which contributes sustainable economic improvement. For this purpose, public awareness about the issue should be improved in the media and necessary trainings should be given to the people in their educations related to the business ethics. Furthermore, legal system in these countries should be improved to have fair income distribution and taxation. Additionally, social responsibility activities should be encouraged, so people with good income will help poor people. Moreover, business partnership system should be improved in which companies can obtain capital from the public and make necessary payments to these people according to the profit amount. This issue positively affects sustainability in economic improvement and welfare society for developing countries.

Originality/value

There are limited studies on sustainable economic development based on Islamic moral-based factors.

Details

International Journal of Islamic and Middle Eastern Finance and Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1753-8394

Keywords

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