On the Manufacturing Defects of Thermoplastic Carbon/Epoxy Composites Manufactured by Automated Tape Placement

2020 ◽  
Author(s):  
Tamer A. Sebaey ◽  
Noel O’Dowd
Keyword(s):  
Solidification Process ◽  
The Other ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Circular Statistics ◽  
Engineering Practice ◽  
Manufacturing Defects ◽  
Thermoset Composites ◽  
Manufacturing Techniques

Abstract Thermoplastic composites are highly recommended for structural application, not only for their superior characteristics derived from the fiber and matrix materials but also for their recycling possibilities, which is a major issue in the today’s engineering practice. The manufacturing techniques for thermoplastics are different from those for the well-established thermoset composites. This paper addresses the quality of the thermoplastic composites by assessing the distribution of the fiber, the void contents and the waviness of the fibers, compared to the thermoset composites. IM7/PEEK and AS4/PA12 are the two thermoplastic composite systems used for this study, whereas, IM7/8552 is the thermoset composite used as reference. The specimens were examined using optical microscopy and computed tomography (CT) and the results were statistically treated using circular statistics. Compared to the IM7/8552 composite, the analysis reveals that the IM7/PEEK and AS4/PA12 composites, manufactured by ATP result in a higher volume of voids. On the other hand, ATP processing improves the alignment of the fibers, as the solidification process occurs while the fibers are in tension. The microscopy studies also show that the ATP manufactured composites have an area in between the different layers of tape with a low number of fibers, compared to the other areas.

scholarly journals Research on the Reform of Civil Engineering Practice Teaching under the Cultivation of Innovation Ability

2019 ◽  
Vol 3 (3) ◽  
pp. 40
Author(s):  
Yibin Guo
Keyword(s):  
Civil Engineering ◽  
Colleges And Universities ◽  
The Other ◽  
Cultural Literacy ◽  
Engineering Practice ◽  
Teaching Reform ◽  
Practice Teaching ◽  
Innovation Ability ◽  
The One

<p>The reform of the current education system has put forward higher requirements on the teaching of colleges and universities. On the one hand, teachers should be responsible for teaching students‘ knowledge and improving students' cultural literacy. On the other hand, they should cultivate students' comprehensive practical ability and innovative ability. Civil engineering major is an important major to train talents for China's economic development. The educational reform of colleges and universities should constantly improve the quality of practical teaching of civil engineering and cultivate talents with strong comprehensive ability for China's economic and social development. At present, the research on the teaching reform of civil engineering is deepening, aiming at improving the quality of civil engineering teaching and promoting the reform of construction course teaching. This paper mainly studies the cultivation of students' innovation ability by the reform of civil engineering practice teaching.</p>

Effect of forming process on mechanical and interfacial properties for thermoplastic composite I-stiffened structures

2021 ◽  
pp. 095400832110515
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang
Keyword(s):  
Bonding Strength ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Forming Process ◽  
Molding Process ◽  
Influencing Mechanism ◽  
Stiffened Structures ◽  
The Common ◽  
Polymer Aging

The forming process is the core factor to control the quality of thermoplastic composite components. In this paper, the common I-stiffened structures in the aerospace field were taken as the research object, and the forming process scheme was designed. Based on the prefabrication of C-shaped parts, the I-stiffened structures were prepared by the compression molding process. The influence law of molding temperature on the quality of the prefabricated C-shaped parts was explored. The time dependence of the PEEK melt viscosity was tested to provide the basis for the optimization of forming process parameters of I-stiffened structures. The influencing mechanism of thermoplastic composites repeatedly forming to the bonding strength of remelting interface was studied. The results show that repeated forming would lead to polymer aging and result in low bonding strength at the remelting interface of the I-stiffened structures. Optimizing the forming process could effectively reduce the aging of materials and improve the bonding strength of the remelting interface and overall mechanical properties of components. The research provides technical guidance for the manufacturing of complex thermoplastic composite components, especially the influence mechanism of the forming process on the bonding strength of remelting interface.

Manufacturing procedure to make flat thermoplastic composite laminates by automated fibre placement and their mechanical properties

2016 ◽  
Vol 30 (12) ◽  
pp. 1693-1712 ◽  
Author(s):  
Suong Van Hoa ◽  
Minh Duc Hoang ◽  
Jeff Simpson
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Composite Structures ◽  
High Speed ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Thermoset Composites ◽  
Material Deposition ◽  
Manufacturing Procedure ◽  
Composites Processing

Automated fibre placement (AFP) is a relatively new process for the manufacturing of composite structures. Among many attractive features, it provides high-speed of material deposition, more repeatability in terms of quality of the part, less labour intensive (as compared with traditional methods of manufacturing such as Hand Lay-Up), less waste and the ability to transition more seamlessly from design to manufacturing. AFP can be used to process both thermoset composites and thermoplastic composites. Thermoplastic composites processing holds many potential benefits. This is because if the process is done right in producing parts with good quality, it is fast since it does not require a second process such as curing in an autoclave or oven. For the purpose of comparison of performance and for design, it is necessary to determine the mechanical properties of laminates made using this process. However, there are challenges in making flat coupons for the purpose of testing for mechanical properties. This article presents these challenges and the procedure developed to make flat laminates using a simple AFP machine. Mechanical properties of these laminates are also determined and compared with those obtained from laminates made using conventional autoclave moulding.

scholarly journals Fibre Alignment and Void Assessment in Thermoplastic Carbon Fibre Reinforced Polymers Manufactured by Automated Tape Placement

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 473
Author(s):  
Tamer A. Sebaey ◽  
Mohamed Bouhrara ◽  
Noel O’Dowd
Keyword(s):  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Ct Scans ◽  
Void Content ◽  
Reinforced Polymers ◽  
Fibre Distribution ◽  
Thermoset Composites ◽  
The Matrix ◽  
Carbon Fibre Reinforced Polymers ◽  
Multiple Melting

Automated Tape Placement (ATP) technology is one of the processes that is used for the production of the thermoplastic composite materials. The ATP process is complex, requiring multiple melting/crystallization cycles. In the current paper, laser-assisted ATP was used to manufacture two thermoplastic composites (IM7/PEEK and AS4/PA12). Those specimens were compared to specimens that were made of thermoset polymeric composites (IM7/8552) manufactured while using a standard autoclave cycle. In order assess the quality, void content, fibre distribution, and fibre misalignment were measured. After manufacturing, specimens from the three materials were assessed using optical microscopy and computed tomography (CT) scans. The results showed that, as compared to the thermoset composites, thermoplastics that are manufactured by the ATP have a higher amount of voids. On the other hand, manufacturing using the ATP showed an improvement in both the fibre distribution inside the matrix and the fibre misalignment.

scholarly journals Investigation of Elastic Tensile Behavior of Thermoplastic Discs Reinforced With Steel Wires

2020 ◽  
pp. 73-76
Author(s):  
Huseyin Firat Kayiran
Keyword(s):  
Numerical Analysis ◽  
Low Temperatures ◽  
Tensile Behavior ◽  
The Other ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Tangential Stresses ◽  
Steel Wires ◽  
Temperature Distributions ◽  
Thermal Stress Distribution

In this study, the stresses occurring in the thermoplastic composite disc were investigated by numerical analysis. Assuming that the modulus of elasticity does not change with temperature, temperature distributions of 20 oC, 40 oC, 60 oC, 80 oC, 100 oC were taken as reference in the study. Composite materials are created by combining the best properties of two or more materials or by creating a new property. Thermoplastic composites, on the other hand, are bendable and ductile. It is vital to know the thermal behavior of these materials, which are preferred in many areas of technology. At the end of the numerical analysis, the radial and tangential stress values calculated at high temperatures; It has been observed that it is greater than the radial and tangential stresses calculated at low temperatures. It has been observed that the tangential stresses are greater than the radial stresses. It was concluded that the increase in the value of the temperature acting on the thermoplastic disc directly affects the thermal stress distribution and values.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

PENERAPAN iLEARNING SURVEY (iSur) DALAM MENINGKATKAN KUALITAS SISTEM INFORMASI SELAMA PROSES PEMBELAJARAN DI PERGURUAN TINGGI RAHARJA

CCIT Journal ◽  
2014 ◽  
Vol 7 (3) ◽  
pp. 335-354
Author(s):  
Untung Rahardja ◽  
Muhamad Yusup ◽  
Ana Nurmaliana
Keyword(s):  
Higher Education ◽  
Student Satisfaction ◽  
Teaching And Learning ◽  
Online Survey ◽  
The Other ◽  
Learning Activities ◽  
Faculty Performance ◽  
Satisfaction Measurement ◽  
Valid Information

The accuracy and reliability is the quality of the information. The more accurate and reliable, the more information it’s good quality. Similarly, a survey, the better the survey, the more accurate the information provided. Implementation of student satisfaction measurement to the process of teaching and learning activities on the quality of the implementation of important lectures in order to get feedback on the assessed variables and for future repair. Likewise in Higher Education Prog has undertaken the process of measuring student satisfaction through a distributed questioner finally disemester each class lecture. However, the deployment process questioner is identified there are 7 (seven) problems. However, the problem can be resolved by the 3 (three) ways of solving problems one of which is a system of iLearning Survey (Isur), that is by providing an online survey to students that can be accessed anywhere and anytime. In the implementation shown a prototype of Isur itself. It can be concluded that the contribution Isur system can maximize the decision taken by the Higher Education Prog. By using this Isur system with questions and evaluation forms are submitted and given to the students and the other colleges. To assess the extent to which the campus has grown and how faculty performance in teaching students class, and can be used as a media Isur valid information for an assessment of activities throughout college.

PENGARUH KUALITAS PRODUK DAN RELIGIUSITAS TERHADAP KEPUTUSAN NASABAH PRODUK SIMPANAN PADA BSM CABANG PURWOKERTO

2017 ◽  
Vol 4 (1) ◽  
pp. 189-215
Author(s):  
Yoiz Shofwa Shafrani
Keyword(s):  
Regression Analysis ◽  
Product Quality ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Analytical Tool ◽  
The Other ◽  
Financial Assets ◽  
Islamic Bank

Perkembangan dunia perbankan syariah tidak lepas dari peran para nasabah yang memberikan kepercayaan terhadap pihak perbankan untuk penyimpanan asset keuangannya. Faktanya banyak kelompok nasabah yang memutuskan untuk menjadi nasabah di perbankan syariah karena faktor religiusitasnya. Faktor lain yang dapat ikut mempengaruhi keputusan nasabah adalah kualitas produk. Di mana kualitas produk merupakan karakteristik yang melekat dari suatu produk. Kemungkinan yang terjadi bahwa kebanyakan nasabah pada perbankan syariah juga masih merupakan nasabah perbankan konvensional.Tujuan yang ingin dicapai dalam penelitian ini adalah untuk mengetahui pengaruh kualitas produk dan tingkat religiusitas nasabah terhadap keputusan nasabah untuk menyimpan dananya atau tidak di BSM Cabang Purwokerto. Alat analisis yang digunakan adalah analisis regresi linier berganda, dengan jumlah sampel 100 nasabah. Diperoleh hasil Y = 5,046 + 0,101X1 + 0,218X2. Berdasarkan uji F yang sudah dilakukan maka dapat diketahui bahwa variabel kualitas produk dan religiusitas secara bersama – sama berpengaruh terhadap keputusan nasabah untuk menyimpan dananya di BSM Cabang Purwokerto. Berdasarkan uji t yang sudah dilakukan dapat diketahui bahwa secara partial baik variabel kualitas produk maupun variabel religiusitas berpengaruh terhadap keputusan nasabah untuk menyimpan dananya di BSM Cabang Purwokerto. The progress of the Islamic bank cannot be separated from the role of its customers who give trust to the bank to deposit their financial assets. It is a fact many groups of customers decide to be the customers of the Islamic bank because of their religiosity. The other influences factor of a customer’s decision is the quality of the product. The aim of this research was to determine the effect of product quality and level of customers’ religiosity towards customers’ decision whether to keep their funds in Syariah Mandiri Bank, Branch of Purwokerto, or not. The analytical tool used was multiple linear regression analysis, with a sample of 100 customers. The results indicate Y = 5,046 + 0,101X1 + 0,218X2. Based on F, it can be seen that both variables of product quality and religiosity simultanously affect the customers’ decision to keep theirfunds in BSM Branch of Purwokerto. Based on t test, it can be seen that independently, either variable of product quality or variables of religiosityinfluences the customers’ decision to keep their funds in BSM Branch of Purwokerto.

CREATING WALKING LED TRANSIT STATIONS FOR WOMEN IN MALAYSIA

2020 ◽  
Vol 7 (1) ◽  
pp. 99
Author(s):  
Yong Adilah Shamsul Harumain ◽  
Nur Farhana Azmi ◽  
Suhaini Yusoff
Keyword(s):  
Quality Of Life ◽  
Developing Countries ◽  
Public Transportation ◽  
Carbon Emission ◽  
The Other ◽  
Walking Distance ◽  
The Road ◽  
On The Road ◽  
Female User

Transit stations are generally well known as nodes of spaces where percentage of people walking are relatively high. The issue is do more planning is actually given to create walkability. Creating walking led transit stations involves planning of walking distance, providing facilities like pathways, toilets, seating and lighting. On the other hand, creating walking led transit station for women uncover a new epitome. Walking becomes one of the most important forms of mobility for women in developing countries nowadays. Encouraging women to use public transportation is not just about another effort to promote the use of public transportation but also another great endeavour to reduce numbers of traffic on the road. This also means, creating an effort to control accidents rate, reducing carbon emission, improving health and eventually, developing the quality of life. Hence, in this paper, we sought first to find out the factors that motivate women to walk at transit stations in Malaysia. A questionnaire survey with 562 female user of Light Railway Transit (LRT) was conducted at LRT stations along Kelana Jaya Line. Both built and non-built environment characteristics, particularly distance, safety and facilities were found as factors that are consistently associated with women walkability. With these findings, the paper highlights the criteria  which are needed to create and make betterment of transit stations not just for women but also for walkability in general.

Piemonte. Tra stasi e sperimentazioni, un quadro chiaroscurale / Piedmont. Between stasis and experimentations, a «chiaroscuro» framework

ARCHALP ◽  
2018 ◽  
pp. 66-75
Author(s):  
Antonio De Rossi ◽  
Roberto Dini
Keyword(s):  
Physical Space ◽  
The Other ◽  
Green Economy ◽  
Urban Centers ◽  
Mountain Areas ◽  
Architectural Production ◽  
New Meanings ◽  
The Alps ◽  
Contemporary Situation

The contemporary architectural production in the Alps of Piedmont has to be studied taking into consideration the contrasting phenomena of depopulation and tourism that have involved the mountain areas of the region during last century. In the fifties and sixties the percentage of abandonment of the high valleys reaches even 80-90%. Entire communities move to industrial urban centers in the cities on the plain. On the other side we witness to a strong polarization of the winter stations that become real “banlieues blanches” for the free time of the citizens and where the architecture of alpine modernism, with various forms, shapes. The paradox nowadays is that the rarefaction of abandoned and depopulated territories is necessary to force to start and choose new innovative paths. We witness a contemporary situation with different shades: on one side the well-established touristic territories that need projects to promote the redevelopment and diversification, on the other side the marginal places where are rising new visions are practices of reactivation of the territory in which architecture is fundamental. The topic of quality of the construction of the physical space intersects with the regeneration of places on a cultural basis, new agriculture and green economy, innovative development of the patrimony, sustainable tourism, with inclusive and participative paths of nature, by giving new meanings to places and building new economies and identities.

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