scholarly journals Thermoplastic Mandrel for Manufacturing Composite Components with Complex Structure

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 399
Author(s):  
Xishuang Jing ◽  
Siyu Chen ◽  
Jiuzhi An ◽  
Chengyang Zhang ◽  
Fubao Xie
Keyword(s):  
Surface Roughness ◽  
Complex Structure ◽  
Internal Quality ◽  
Good Shape ◽  
Average Porosity ◽  
Complex Shapes ◽  
Thickness Error ◽  
Formed Part ◽  
Formed Structure

This study was to solve the mandrel demolding problem after curing the composite component with complex structure. In this paper, a reusable thermoplastic mandrel with heating softening characteristics was developed by resin transfer molding (RTM). The glass transition temperature (Tg), surface roughness, and reusability of the mandrel, as well as the shape, surface roughness, thickness uniformity, and internal quality of the formed structure, were tested. The result showed that the Tg of the mandrel was between 80 and 90 °C and the surface roughness was less than Ra 0.5 μm. Additionally, the mandrel can be recycled and can still maintain a good shape after 20 times of deformation. By using this method, the demolding process can be realized by heating and softening the mandrel. The profile error of the formed structure was within 0.5 mm, the surface roughness was less than Ra 0.5 μm, the thickness error was within 0.2 mm, and the average porosity of the upper and lower halves of composite parts was 0.72% and 0.61%. All those data showed that the formed part was in good shape and of good quality. The thermoplastic mandrel can solve the demolding problem of composite materials with complex shapes.

ANALYSIS OF THE CORRELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE SIGNAL AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
Cutting Forces ◽  
End Milling ◽  
Complex Structure ◽  
Machined Surface ◽  
End Mills ◽  
Machining Operations

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.

DECODING OF THE RELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950054 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
TECK SENG CHANG
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
End Milling ◽  
Complex Structure ◽  
Dry Machining ◽  
End Mill ◽  
Milling Operation ◽  
Machining Operations

Analysis of the surface quality of workpiece is one of the major works in machining operations. Variations of cutting force is an important factor that highly affects the quality of machined workpiece during operation. Therefore, investigating about the variations of cutting forces is very important in machining operation. In this paper, we employ fractal analysis in order to investigate the relation between complex structure of cutting force and surface roughness of machined surface in end milling operation. We run the machining operation in different conditions in which cutting depths, type of cutting tool (serrated versus square end mills) and machining conditions (wet and dry machining) change. Based on the obtained results, we observed the relation between complexity of cutting force and surface roughness of generated surface of machined workpiece due to engagement with the flute surface of end mill, in case of using square end mill in dry machining condition, and also in case of using serrated end mill in wet machining condition. The fractal approach that was employed in this research can be potentially examined in case of other machining operations in order to investigate the possible relation between complex structure of cutting force and surface quality of machined workpiece.

scholarly journals Technological assurance of the quality of processing of products from aluminum alloys with a complex geometric shape using magnetic abrasive processing

2021 ◽  
Vol 326 ◽  
pp. 00033
Author(s):  
Dmitriy Maksimov ◽  
Radmila Shcheglova ◽  
Dmitriy Klochkov
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloys ◽  
Theoretical Study ◽  
Geometric Shape ◽  
Exponential Dependence ◽  
Corrosion Resistant ◽  
Complex Geometric Shape ◽  
Complex Shapes

In the presented article, the issue of the implementation of magnetic abrasive processing is considered in order to ensure the quality of surfaces of complex shapes of parts made of corrosion-resistant aluminum alloys. The implementation was carried out through theoretical and experimental research. In a theoretical study, the features of processing corrosion-resistant aluminum alloys, existing and possible schemes for magnetic-abrasive processing of surfaces of complex geometric shapes, including a combination of various working movements of the workpiece and pole pieces, are considered. In an experimental study, the dependence of the quality of the processed surface (roughness) on the size of the working gap between the workpiece and the working pole was determined. The result of the research is the determination of the optimal treatment schemes for surfaces with a complex geometric shape, as well as the derived exponential dependence of the change in surface roughness on the size of the working gap.

Study on the Quality Evaluating Methods of Laser Forming Based on Thermal Stress

2010 ◽  
Vol 426-427 ◽  
pp. 127-131
Author(s):  
Yi Jun Zhou ◽  
Yong Kang Zhang ◽  
W.M. You ◽  
Y.G. Huang
Keyword(s):  
Mechanical Property ◽  
Surface Roughness ◽  
Thermal Stress ◽  
Evaluation System ◽  
Surface Defects ◽  
Surface Hardness ◽  
Internal Quality ◽  
Laser Forming ◽  
Surface Residual Stress

People are in dire need of knowing whether the workpiece is satisfactory after laser forming while using the technology of laser forming with thermal stress. In order to solve the difficult problem of how to evaluate the quality of laser forming with thermal stress, surface quality evaluating indexes have been studied firstly; surface defects, surface roughness and surface association mechanical property (such as surface hardness, surface constitution, surface residual stress) are considered as primary measuring indexes of laser forming quality; the internal quality of laser forming is rested with the quality of forming area. Surface defects and their methods of calibration, surface roughness and its method of measurement, surface association mechanical property and its methods of measurement are introduced respectively. In the meantime, how to establish the quality evaluating system of laser induced thermal stress forming work pieces has been discussed, the work should be carried out after conforming to evaluation system, evaluation indexes and evaluation criterion.

Relation between Surface Roughness and Overlap Interval in Fused Deposition Modeling

2011 ◽  
Vol 264-265 ◽  
pp. 1625-1630 ◽  
Author(s):  
Dae Keon Ahn ◽  
Jin Hwe Kweon ◽  
Jin Ho Choi ◽  
Seok Hee Lee
Keyword(s):  
Surface Roughness ◽  
Manufacturing Process ◽  
Fused Deposition Modeling ◽  
Layered Manufacturing ◽  
Fused Deposition ◽  
Complex Shapes ◽  
Deposition Modeling ◽  
High Level ◽  
Surface Angle

Rapid prototyping (RP) can efficiently fabricate high level models with complex shapes. Hence the RP has been widely applied in various industrial fields. However, as the technology is inherently performed by layered manufacturing process, the surface quality of the RP part is not satisfactory to use general industrial purpose. This is the reason that surface roughness problem has been key issue in RP. In this paper, relation between surface roughness and overlap interval is investigated based on a surface roughness formulation in fused deposition modeling (FDM). Additionally, effects of surface angle and filament shape are analyzed and discussed to predict surface roughness distribution by the overlap interval variation.

scholarly journals The Influence of the Shape of Grooves on the Intensity of Closing Axial Material Discontinuities During Rolling

2015 ◽  
Vol 60 (1) ◽  
pp. 461-468 ◽  
Author(s):  
K. Sobczak ◽  
H. Dyja ◽  
A. Kawałek
Keyword(s):  
Experimental Studies ◽  
Rolling Process ◽  
Production Method ◽  
Internal Quality ◽  
Axial Porosity ◽  
Surface Areas ◽  
Initial Stage ◽  
Complex Shapes ◽  
Material Discontinuities

Abstract The article discusses the influence of rolling in the newly designed slitting-bending grooves on closing internal material discontinuities in continuous ingots. The defects located in the axial area of a strand, i.e. axial porosity and contraction cavity, were analysed. Numerical and experimental studies of the rolling process of flat bars for feedstock with marked materials discontinuities simulating actual defects occurring in an ingot were conducted. For comparison purposes, rolling of feedstock with discontinuities in traditional grooves was conducted. The numerical simulations were carried out using the Forge 2008¯software programme. The experimental studies were conducted in a D150 laboratory rolling mill. In the research, the S355J2G3 structural steel and lead were used. Distributions of temperature, intensity of deformation and stress in a cross-section of strands after rolling were analysed. Changes in the surface areas of the discontinuities in feedstock after rolling in shape and traditional grooves were examined. It was concluded that introduction of grooves with complex shapes may contribute to the improvement of internal quality of finished products. The complex shape of the tools has allowed for an almost 100% closure of the discontinuities located in the central part of a strand, already at the initial stages of the process, unlike in case of the traditional production method, where the discontinuities were transferred even until the final product. Applying the newly designed slitting-bending grooves enables utilisation of a smaller number of edge grooves at the initial stage of the rolling process, where reopening of freshly welded defects might occur.

Improving of quality of gate assembly contact surfaces of high-pressure fi ttings by diamond burnishing

2020 ◽  
pp. 99-104
Author(s):  
S.A. Zaydes ◽  
A.N. Mashukov ◽  
T.Ya. Druzhinina
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
Main Part ◽  
Conical Surface ◽  
The Real ◽  
Metal Seal ◽  
Diamond Burnishing ◽  
Air Tightness ◽  
Contact Surfaces

The contact belt of the gate assembly is the main part of high pressure fittings. The serviceability of the fittings assembly as whole depends on the air-tightness and quality of the mating surfaces. The technology of diamond burnishing allows to increase the interface of the nodes by red ucing the surface roughness of the metal-to-metal seal. The real experience for improving of the fittings contact belt due to the use of diamond burnishing of the nozzles seats and the conical surface of the rods.

Nondestructive Quality Evaluation of Tomatoes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 544c-544
Author(s):  
A. Hakim ◽  
A. Purvis ◽  
E. Pehu ◽  
I. Voipio ◽  
E. Kaukovirta
Keyword(s):  
Quality Evaluation ◽  
Tomato Fruit ◽  
Quality Attributes ◽  
Internal Quality ◽  
Attractive Alternative ◽  
Fluorescence Techniques ◽  
Nondestructive Quality ◽  
Alternative Techniques ◽  
Evaluation Techniques

Both external and internal quality of fruits such as tomatoes can be evaluated by different methods, but all most all of the methods are destructive. For this reason, there is a need to reassess some of the alternative techniques. Nondestructive quality evaluation is an attractive alternative. The principles of different nondestructive quality evaluation techniques such as optical, physical, and fluorescence techniques applied to tomato fruit is explained. Successful application of these techniques that could be used for evaluation of different quality attributes are illustrated. The advantages of nondestructive quality evaluation techniques are that they are very fast, easy, labor- and time-intensive, and inexpensive. These techniques could also be useful to evaluate the quality of other vegetables.

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