V. Chowdary Boppana and Fahraz Ali
This paper presents an experimental investigation in establishing the relationship between FDM process parameters and tensile strength of polycarbonate (PC) samples using the…
Abstract
Purpose
This paper presents an experimental investigation in establishing the relationship between FDM process parameters and tensile strength of polycarbonate (PC) samples using the I-Optimal design.
Design/methodology/approach
I-optimal design methodology is used to plan the experiments by means of Minitab-17.1 software. Samples are manufactured using Stratsys FDM 400mc and tested as per ISO standards. Additionally, an artificial neural network model was developed and compared to the regression model in order to select an appropriate model for optimisation. Finally, the genetic algorithm (GA) solver is executed for improvement of tensile strength of FDM built PC components.
Findings
This study demonstrates that the selected process parameters (raster angle, raster to raster air gap, build orientation about Y axis and the number of contours) had significant effect on tensile strength with raster angle being the most influential factor. Increasing the build orientation about Y axis produced specimens with compact structures that resulted in improved fracture resistance.
Research limitations/implications
The fitted regression model has a p-value less than 0.05 which suggests that the model terms significantly represent the tensile strength of PC samples. Further, from the normal probability plot it was found that the residuals follow a straight line, thus the developed model provides adequate predictions. Furthermore, from the validation runs, a close agreement between the predicted and actual values was seen along the reference line which further supports satisfactory model predictions.
Practical implications
This study successfully investigated the effects of the selected process parameters - raster angle, raster to raster air gap, build orientation about Y axis and the number of contours - on tensile strength of PC samples utilising the I-optimal design and ANOVA. In addition, for prediction of the part strength, regression and ANN models were developed. The selected ANN model was optimised using the GA-solver for determination of optimal parameter settings.
Originality/value
The proposed ANN-GA approach is more appropriate to establish the non-linear relationship between the selected process parameters and tensile strength. Further, the proposed ANN-GA methodology can assist in manufacture of various industrial products with Nylon, polyethylene terephthalate glycol (PETG) and PET as new 3DP materials.
Details
Keywords
Boppana V. Chowdary, Ayanna‐Rene De Noon, Fahraz Ali and Clement A.C. Imbert
The purpose of this paper is to provide a comprehensive work flow for the improvement of the Reverse Engineering (RE) process in producing non‐uniform rational B‐splines (NURBS…
Abstract
Purpose
The purpose of this paper is to provide a comprehensive work flow for the improvement of the Reverse Engineering (RE) process in producing non‐uniform rational B‐splines (NURBS) models from scanned point cloud data. This should become a reliable guide in the creation of desired 3D‐CAD models in order to improve efficiency of downstream operations and further to make decisions regarding quality control.
Design/methodology/approach
The paper deals with a detailed investigation of operations in achieving an object's accuracy in the data editing phase and data fitting phase that employs the use of a 3D scanner. A case example involving the ShapeGrabber® AI310 laser scanner was used in digitizing the physical object. Operations considered for investigation at the data editing phase include relaxation, decimation of triangles and sharpening of edges. Contour detection, construct patches, target patch count, grid construction and grid resolution are selected as the operations for investigation in the data fitting phase. Evaluation of the generated digitized models was carried out by performing tests which include 3D Comparisons and Geometric Dimensioning and Tolerance (GD & T) testing.
Findings
The process of data editing is considered to be extremely time consuming which requires a high degree of skill in order to carry out the data manipulation steps. For the purpose of investigation, an electrical socket cover was considered as the object for digitization. The study found some contributors to enhance the quality of the digital model that can be used in the first piece inspection. The results indicate that although the operations associated with the data fitting phase affect the overall quality of the digitized model; they are however, limited by whatever the quality achieved at the data editing phase.
Practical implications
The RE work flow described in this research will assist designers and practitioners in improving both the efficiency and effectiveness of design and manufacturing functions.
Originality/value
The data editing and fitting processes are time consuming due to various adjustments necessary in obtaining a NURBS model from the digitized data. Thus, the proposed RE work flow identified the steps to realize the desired CAD models from the point cloud data. Moreover, from this study, practitioners will get a concise overall understanding about which geometrical features need to be adjusted so that the required model can be achieved; instead of the need to develop this procedure by themselves through the process of trial and error.
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Fahraz Ali, Boppana V. Chowdary and Luis Gonzales
The purpose of this paper is to present an integrated design approach for rapid product development (RpD) of a broken product.
Abstract
Purpose
The purpose of this paper is to present an integrated design approach for rapid product development (RpD) of a broken product.
Design/methodology/approach
Reverse engineering (RE), re‐engineering (ReE) and RpD systems have been incorporated to infuse agile characteristics in the proposed design and development process. A case study involving a broken clutch shoe was selected to demonstrate the efficacy of the proposed integrated approach.
Findings
Integration of RE, ReE and RpD presented an unconventional approach towards achieving reduced lead times for design and development of products. Agile characteristics have been manifested for the broken clutch shoe by retrieval of a digitized parametric computer aided design (CAD) model. Moreover, development and selection of an enhanced feasible design (M3) as well as delivery of the corresponding prototype was accomplished just in one week.
Originality/value
The proposed integrated approach for RpD can provide solutions to similar industrial situations wherein agility in the product design and development process can be infused so that the developed part can be delivered quickly to the customer at the reduced time and costs.