scholarly journals Slug rivet assembly modeling and effects of procedure parameters on the quality of riveted lap joints

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879839 ◽  
Author(s):  
Changyi Lei ◽  
Yunbo Bi ◽  
Jiangxiong Li ◽  
Yinglin Ke

Slug rivet interference-fit riveting is one of the advanced connection technologies which has been widely applied in aerospace manufacture. This article presents an appropriate numerical model simulating the slug rivet upset process with countersunk hole structure. Many previous studies have focused on the riveted lap joints without countersunk hole structure and ignored its related process parameters. The main difference is that the hole expansion would be inhomogeneous through the thickness direction due to the impact of countersunk hole. To improve the riveting quality and reduce the inhomogeneity scale of the interference distribution, the effects of two procedure parameters have been assessed. The analysis results significantly improve knowledge about the slug rivet installation process as well as the effects of the corresponding process parameters. The study will pave the way for further investigations.

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 103
Author(s):  
Jin Mark D. G. Pagulayan ◽  
Aprille Suzette V. Mendoza ◽  
Fredelyn S. Gascon ◽  
Jan Carlo C. Aningat ◽  
Abigail S. Rustia ◽  
...  

The study aimed to evaluate the effects of process parameters (time and raw material weight (RMW)) of conventional (boiling for 10–45 min) and microwave-assisted (2–8 min) aqueous extraction on the color quality (i.e., lightness (L*), chroma (C*), and hue (H°) of anthocyanin –based colorants of red and Inubi sweet potato (Ipomoea batatas L.) leaves. Using response surface methodology, it was found that RMW and boiling time (BT) and microwave time (MT) generally had a significant (p < 0.05) effect on the color quality of the extract from both extraction methods. The effects were found to vary depending on the extraction method and variety of the leaves used. Both extraction methods produced a brown to brick-red extract from the Inubi variety that turned red-violet to pink when acidified. The red sweet potato leaves produced a deep violet colored extract that also turned red-violet when acidified. It is recommended that the anthocyanin content of the extracts be measured to validate the impact of the methods on the active agent. Nevertheless, the outcomes in this study may serve as baseline data for further studies on the potential of sweet potato leaf colorants (SPLC) as a colorant with functional properties.


2007 ◽  
Vol 353-358 ◽  
pp. 1931-1934
Author(s):  
Wurikaixi Aiyiti ◽  
Wan Hua Zhao ◽  
Yi Ping Tang ◽  
Bing Heng Lu

A direct metal RP (rapid prototyping) process based on micro-plasma arc welding (MPAW) is presented. The impact of R (ratio of width to height of the deposited track’s cross-section) on part quality is investigated. Taguchi method is adopted to analyze the effect of each process parameter on R, and the optimized process parameters are obtained. The results show that the quality of the parts with larger R is better than that with smaller R, and the peak current, duty cycle of pulse duration, wire-feeding speed, scanning speed and plasma gas flow rate all exert significant effects on R. The overlapped surface smoothness, tensile strength and elongation of the parts fabricated with optimized parameters are measured to show obviously better performances than those of the parts fabricated with ordinary process parameters.


2020 ◽  
Vol 184 ◽  
pp. 01029
Author(s):  
Bairoju Shankarachary ◽  
N Sateesh ◽  
Lavu Gopinath ◽  
Siripuram Aparna

Vacuum assisted resin transfer molding (VARTM) is one of the manufacturing technique that is viable for production of fiber reinforced polymer composite components suitable for aerospace, marine and commercial applications. However the repeatable quality of the product can be achieved by critically fixing the process parameters such as Vacuum Pressure (VP) and permeability of the preform. The present investigation is aimed at studying the effect of permeability for production of Glass Fiber Reinforced Polyester (GFRP) components with consistent quality. The VARTM mould is made with an acrylic transparent top cover to observe and record the resin flow pattern. Six layers of randomly placed glass fiber under five different vacuum pressures VP1 = 0.013, VP2 = 0.026, VP3 = 0.039, VP4 = 0.053 and VP5 = 0.066 MPa were studied. The laminates produced by this process under the above mentioned conditions were characterized with ASTM D procedures so as to study the effect of these process parameters on the quality of the laminate. And as mentioned there is a considerable effect of permeability on the impact strength and the void content in the laminates under different vacuum pressures. SEM analysis of the impact tested fractured GFRP composites showed the bonding of fiber and matrix.


2013 ◽  
Vol 315 ◽  
pp. 171-175 ◽  
Author(s):  
Mohd Hilmi Othman ◽  
Sulaiman Hasan ◽  
Suriati Rasli

The objective of this study is to analyze the main parameter setting in injection moulding that influenced the processing of selected thermoplastics components. The test sample used for this project was a hinge made from Polypropylene (PP). This sample was being utilised to analyse the parameters affecting the quality of plastic products, which were warpage and shrinkage. Computer-Aided Engineering (CAE) was applied through CadMould 3D-F simulation software. The processing parameters such as filling time, melt temperature, wall temperature and cooling time were selected to determine the quality of the product. By adopting Taguchi Method, the orthogonal array, Signal-to-Noise (S/N) ratio and Analysis of Variance (ANOVA) were used to find the optimum levels as well as to indicate the impact of the process parameters on warpage and shrinkage. The verification test was also performed to prove the effectiveness of Taguchi technique after the optimum levels of process parameters. The ANOVA results show that cooling time and wall temperature are found to be the most significant factors for shrinkage and warpage, with the contribution of 66.96% and 56.82% respectively. The verification test with the optimal settings shows that warpage were improved by about 0.4% and shrinkage with 4.2% improvement. These findings are useful for production engineer to determine optimal parameter during performing injection moulding on hinges products.


Author(s):  
Antonio Lanzotti ◽  
Massimo Martorelli ◽  
Gabriele Staiano

With a view to enabling additive manufacturing (AM) processes, today, open-source, low-cost 3D printers are systems with great potential. However there is a significant lack of scientific data on the performance of open-source 3D systems and on the selection of adequate process parameters that can help to improve the quality of the parts. The purpose of this paper is to assess the effects of the main process parameters on the dimensional accuracy of a specific open-source 3D printer, the RepRap Prusa-Mendel I2. This study consisted of a benchmarking part, involving elementary shapes representing a series of different features. By means of a full factorial DoE (Design of Experiments), with three factors (layer thickness, deposition speed, and flow rate), three levels, and three replications, 81 parts were obtained. Subsequently, a laser scanner (D700 Laser Scanner—3Shape, Denmark) was used as high resolution reverse engineering system in order to evaluate the variation between real parts and nominal geometry. The impact of the main process parameters was evaluated and optimal combinations were analyzed. On the basis of the results obtained in the experiments, practical suggestions for the settings of common process parameters were formulated. Test results serve to improve the quality of AM parts through the most appropriate selection of the main process parameters.


Author(s):  
Sanjay Sharma ◽  
Dennis A. Siginer

Quality of laminates produced by Seeman Composite Resin Infusion Molding Process (SCRIMP) is studied by comparing their Fiber Volume fraction and void content. SCRIMP is a variant of Vacuum Assisted Resin Transfer Molding (VARTM). Manufacturing process parameters are then identified and varied to study the impact on mechanical properties of laminated composites. Modification to SCRIMP is carried out by infusing the resin under additional pressure. Optimal process parameters for this modified SCRIMP process are suggested to yield laminates that are repeatable and consistent in quality. Void content is reduced in the composite laminates by altering the vacuum pressure level. Thickness gradient commonly found in SCRIMP processed laminates is eliminated by allowing longer de-bulking time. Final laminate quality is measured using ASTM standardized mechanical testing.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2298 ◽  
Author(s):  
Magdalena Machno

Advanced engineering materials (e.g., nickel or titanium alloy) are being increasingly applied to produce parts of gas turbines in the aerospace industry. To improve the durability of these parts, many holes, with a length-to-diameter aspect ratio greater than 20:1, are created in their structure. The quality of the holes significantly affects the cooling process of the elements. However, it is challenging to machine materials by conventional methods. When machining a hole with a high aspect ratio, the major problem is effective flushing of the machining area, which can improve the hole’s surface integrity and dimensional accuracy. Consequently, the electro-discharge drilling (EDD) process is good alternative for this application. This paper presents the results of an analysis of the EDD of Inconel 718 alloy. An experiment was conducted to evaluate the impact of process parameters (pulse time, current amplitude, and discharge voltage) on the process’s performance (linear tool wear, taper angle, drilling speed, the hole’s aspect ratio, and surface roughness (Ra and Rz)). The results show that EDD provides us with the possibility to drill holes with an aspect ratio greater than 10:1. The results also demonstrate that holes with an aspect ratio greater than 10:1 and a small taper angle value have a significantly decreased quality of internal surface, especially at the bottom of the hole. This indicates that an insufficient amount of debris is removed from the bottom of the hole.


2020 ◽  
Vol 29 (4) ◽  
pp. 2097-2108
Author(s):  
Robyn L. Croft ◽  
Courtney T. Byrd

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.


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