scholarly journals Development of Novel Test Specimens for Characterization of Multi-Material Parts Manufactured by Material Extrusion

2018 ◽  
Vol 8 (8) ◽  
pp. 1220 ◽  
Author(s):  
Hagen Watschke ◽  
Lennart Waalkes ◽  
Christian Schumacher ◽  
Thomas Vietor

Multi-material additive manufacturing (AM) offers new design opportunities for functional integration and opens new possibilities in innovative part design, for example, regarding the integration of damping or conductive structures. However, there are no standardized test methods, and thus test specimens that provide information about the bonding quality of two materials printed together. As a result, a consideration of these new design potentials in conceptual design is hardly possible. As material extrusion (ME) allows easily combination of multiple polymeric materials in one part, it is chosen as an AM technique for this contribution. Based on a literature review of commonly used standards for polymer testing, novel test specimens are developed for the characterization of the bonding quality of two ME standard materials printed together. The proposed specimen geometries are manufactured without a variation of process parameters. The load types investigated in the course of this study were selected as examples and are tensile, lap-shear, and compression-shear. The conducted tests show that the proposed test specimens enable a quantification of the bonding quality in the material transition. Moreover, by analyzing the fracture pattern of the interface zone, influencing factors that probably affect the interface strength are identified, which can be further used for its optimization.

2015 ◽  
Vol 1122 ◽  
pp. 141-144
Author(s):  
Tereza Komárková ◽  
Monika Králíková ◽  
Dalibor Kocáb ◽  
Petr Misák ◽  
Tomáš Stavař

The durability of concrete can be assessed based on the quality of the surface layer of concrete, for which there are a few standardized assessment test methods. Usually, the quality of the surface layer of concrete is evaluated based on its air and water permeability. The aim of this experiment was to compare the outputs which provide some methods for determining the permeability of the surface layer of concrete (GWT, ISAT, TPT, the depth of penetration of water under pressure). The measured values using the individual methods of assessing the permeability of the surface layer of concrete very closely correspond.


2019 ◽  
Vol 211 ◽  
pp. 217-227 ◽  
Author(s):  
Michael Dugmore ◽  
Michela Nocetti ◽  
Michele Brunetti ◽  
Zahra Naghizadeh ◽  
C. Brand Wessels

2008 ◽  
Vol 98 (3) ◽  
pp. 229-238 ◽  
Author(s):  
Angel Camp Faulí ◽  
Cristina Llobell Andrés ◽  
Norberto Porta Rosas ◽  
Maria José Fernández ◽  
Enrique Montiel Parreño ◽  
...  

Background: The selection of materials for the production of multilayer insoles for diabetic feet is a difficult task owing to the lack of technical information about these materials. Therefore, objective criteria were established for the selection of these materials. Methods: Mechanical- and comfort-related tests for the mechanical characterization of different materials and their combinations were considered. These tests were conducted according to standardized test methods for polymeric cellular materials. Results: Criteria for the use of cellular materials were obtained. The properties of accommodation, cushioning, and filling materials were established and the most adequate polymer nature for each of the three applications was identified. Variables that affect the properties of these material combinations were studied. Conclusions: These test results will allow podiatrists to select insoles in a more objective way, thus achieving a more successful treatment for diabetic foot-related injuries. (J Am Podiatr Med Assoc 98(3): 229–238, 2008)


Author(s):  
O. Marko ◽  
V. Livinskaya ◽  
E. Korbut

В материале статьи изложены результаты исследований влияния отечественной комплексной химической добавки ( УКД-1 ), содержащей структурированный углеродный наноматериал (УНМ) и характеризующейся совмещенным (ускоряющим твердение и пластифицирующим) эффектом, на изменения во времени формуемости бетонных смесей и на кинетику твердения бетона в беспрогревном варианте технологии монолитного бетонирования. Целью исследований являлось установление закономерностей изменения формуемости (осадки конуса) подвижных бетонных смесей с добавкой УКД-1 во времени в зависимости от изменяющихся факторов свойств цемента, температуры, условий транспортирования для разработки соответствующих рекомендаций по использованию этой новой добавки в монолитном бетоне. При выполнении экспериментальных исследований использовали стандартизированные методы испытаний. В результате установлено, что влияние добавки УКД-1 на сохранение формовочных свойств бетонных смесей подчиняется общим закономерностям, характерным для входящих в ее состав пластифицирующего и ускоряющих твердение бетона веществ, и определена допускаемая продолжительность транспортирования смесей с этой добавкой в диапазоне температуры от 05 оС до 2530 оС, что обеспечивает необходимые условия для ведения бетонных работ. С использованием стандартизированных и оригинальных методик экспериментально выявлены закономерности роста прочности тяжелого цементного бетона под влиянием отдельно взятого ускоряющего компонента добавки УКД-1 и этой добавки в зависимости от ее дозировки (в диапазоне 0,52,0 от массы цемента). Экспериментально оценены зависимости темпа роста бетона с добавкой УКД-1 от основных технологических факторов качества цемента, величины водоцементного отношения, состава бетона и консистенции бетонной смеси, температуры среды твердения и теплоизолирующих характеристик форм-опалубок. Это позволило обосновать рациональные режимы и параметры условий твердения бетона с добавкой УКД-1 для обеспечения прочности (на сжатие) в диапазоне 50100 от требуемой в проектном возрасте (28 сут.) без затрат энергии на ускорение его твердения.The results of researches of influence of domestic complex chemical additive ( UKD-1 ), containing the structured carbon nanomaterial (CNM) characterized by the combined (the accelerating curing and plasticizer) effect on the time variation of the formability of concrete mixtures and on kinetics of curing of concrete in technology of monolithic concreting technology without warming up are expounded in the article. The aim of this study was to establish patterns of change in formability (slump) of flowable concrete mixtures with the addition of UKD-1 in time depending on the varying factors: the properties of the cement, the temperature conditions of transportation, and to develop appropriate recommendations for the use of this new additive in monolith concrete. In carrying out experimental studies using standardized test methods. As a result, found that the influence of the additive UKD-1 for the preservation of the molding properties of concrete mixtures follows the general laws specific to its constituent plasticizing and accelerating the hardening of concrete materials, and defined the permissible duration of transportation with these additive mixtures in the temperature range from 0...5 C to 25...30 C, that provides the necessary conditions for year-round maintenance of concrete work. Standardized and original methods has reviled the regularities of growth of the strength of heavy cement concrete under the influence of the separately taken accelerating component of the additive UKD-1 and this additive, depending on the dosage (in the range (0,5...2,0) of the mass of cement)). The dependence of the growth rate of concrete with the additive of UKD-1 from the basic technological factors quality of cement, the values of water-cement ratio, concrete composition and consistency of the concrete mix, ambient temperature curing and heat-insulating characteristics form formwork experimentally evaluated. This proved the rational modes and parameters of the conditions of concrete hardening with the addition of UKD-1 for strength (compression) in the range of (50...100) of the required project in the aged (28 days), without cost of energy to accelerate its hardening.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Dietmar Drummer ◽  
Andreas Seefried ◽  
Steve Meister

Injection moulding of polymer microparts can result in modified material behaviour due to process-induced changes in the internal properties. Thus, a transfer of the mechanical material properties in microparts, determined and valid on standardized test specimens, is only partially possible and should be verified on microtest specimens. This paper investigates both tensile and bending test methods for a suitable characterization of material stiffness in polymer microparts. For this purpose a down-scaled standard specimen is used and tested with different testing methods. The investigations reveal that the different testing methods result in comparable mechanical values. The effects of process-induced modified mechanical behaviour are observable in the investigated testing methods. Consequently, a microbending test is potentially a suitable method for characterizing material stiffness using microspecimens.


Ultrasonics ◽  
2020 ◽  
Vol 106 ◽  
pp. 106140 ◽  
Author(s):  
Michaela Janovská ◽  
Petr Sedlák ◽  
Jan Cizek ◽  
Martin Koller ◽  
Filip Šiška ◽  
...  

2016 ◽  
Vol 28 (6) ◽  
pp. 726-735
Author(s):  
Mohammad Tajul Islam ◽  
Mohammad Rafiqur Rashid ◽  
Md Rafiqul Islam Rana

Purpose The properties of polyester/cotton (PC) fabric after chemical treatments as lining in woolen suits has been investigated, as the purpose of this paper is to study the influence of different finishing agents and their concentration on the properties of PC fabrics. Design/methodology/approach Three different chemical finishes such as anti-slip finish, softener and moisture management finish were applied to currently popular 80/20 PC pocketing fabric at three different concentration levels. A total of 60 seams were produced from 2/1 twill woolen shell fabric and chemically treated lining. Six important tests defining comfort and seam’s quality of lining fabric were chosen, namely, seam strength, seam slippage, stiffness, drape, water vapor transmission (WVT), abrasion resistance to study its properties and testing were done as per standardized test methods. Findings Chemical treatments affect the properties of PC fabric used as lining significantly in terms of seam strength, seam slippage, WVT and abrasion resistance. Among the three applied chemical finishes softener, at 20, 40 and 60 g/l, was found to be the best choice to make PC fabric suitable in terms of seam performance, durability, drape and comfort for use lining in suits with economic advantage. Originality/value The paper contributes to understanding the properties of relatively cheap 80/20 PC pocketing fabric used as lining in a suit.


Author(s):  
Florina Violeta Anghelina ◽  
Dan Nicolae Ungureanu ◽  
Carmen Popa ◽  
Elena Valentina Stoian ◽  
Ileana Nicoleta Popescu ◽  
...  

Abstract In this presentation are evidenced instrumental characterization by Electronic Scanning Microscopy (SEM) equipped with EDS / WDS of aluminum alloys such 2024 alloy with multiple synergistic purposes as: acquisition of new knowledge, increase the amount of information obtainable about the material, increasing the efficiency and the quality of the tests, characterization of special destination alloys and assessing their conformity with the specified requirements. In this direction, it requires both the knowledge the test methods (theoretical basis, test method, procedure relating to the method, quality assurance testing) as well material characteristics investigated. These aspects are necessary for test system design, and preliminary interpretation of experimental results.


1999 ◽  
Vol 105 (2) ◽  
pp. 954-954
Author(s):  
Dimitri Donskoy ◽  
Alexander Ekimov ◽  
Alexander Sutin

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