scholarly journals Characterization of Material Stiffness on Injection Moulded Microspecimens Using Different Test Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Dietmar Drummer ◽  
Andreas Seefried ◽  
Steve Meister
Keyword(s):  
Standardized Test ◽  
Standard Specimen ◽  
Test Methods ◽  
Bending Test ◽  
Material Behaviour ◽  
Testing Methods ◽  
Material Stiffness ◽  
Internal Properties ◽  
Induced Changes

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.

Physical Evaluation of Insole Materials Used to Treat the Diabetic Foot

2008 ◽  
Vol 98 (3) ◽  
pp. 229-238 ◽  
Author(s):  
Angel Camp Faulí ◽  
Cristina Llobell Andrés ◽  
Norberto Porta Rosas ◽  
Maria José Fernández ◽  
Enrique Montiel Parreño ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Standardized Test ◽  
Technical Information ◽  
Test Methods ◽  
Cellular Materials ◽  
Test Results ◽  
Filling Materials ◽  
Materials Used ◽  
Selection Of

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)

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
Keyword(s):  
Standardized Test ◽  
Functional Integration ◽  
Polymeric Materials ◽  
Test Methods ◽  
Fracture Pattern ◽  
Bonding Quality ◽  
Material Extrusion ◽  
Lap Shear

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.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

TEST METHODS FOR POLYORGANOSILOXANE COMPOSITIONS USED AS PROTECTIVE COATINGS IN ELECTRONIC INSTRUMENTATION

2020 ◽  
Author(s):  
Ольга Владимировна Неёлова ◽  
Людмила Муратовна Кубалова ◽  
Анна Петровна Деревщикова
Keyword(s):  
Protective Coatings ◽  
Test Methods ◽  
Testing Methods ◽  
Organosilicon Polymer ◽  
Electronic Instrumentation

Представлен обзор по методам испытаний кремний органических полимерных композиций, применяемых в качестве защитных покрытий в современном электронном приборостроении. A review is given of testing methods for organosilicon polymer compositions used as protective coatings in modern electronic instrumentation.

scholarly journals Bending Setups for Reliability Investigation of Flexible Electronics

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Rafat Saleh ◽  
Maximilian Barth ◽  
Wolfgang Eberhardt ◽  
André Zimmermann
Keyword(s):  
Flexible Electronics ◽  
Test Methods ◽  
Bending Test ◽  
Flexible Systems ◽  
Flexible Displays ◽  
Dynamic Bending

Flexible electronics is a rapidly growing technology for a multitude of applications. Wearables and flexible displays are some application examples. Various technologies and processes are used to produce flexible electronics. An important aspect to be considered when developing these systems is their reliability, especially with regard to repeated bending. In this paper, the frequently used methods for investigating the bending reliability of flexible electronics are presented. This is done to provide an overview of the types of tests that can be performed to investigate the bending reliability. Furthermore, it is shown which devices are developed and optimized to gain more knowledge about the behavior of flexible systems under bending. Both static and dynamic bending test methods are presented.

Characterization of the baking-induced changes in starch molecular and crystalline structures in sugar-snap cookies

2021 ◽  
Vol 256 ◽  
pp. 117518
Author(s):  
Zhongwei Zhang ◽  
Xiangyun Fan ◽  
Hongxiang Ma ◽  
Cheng Li ◽  
Enpeng Li ◽  
...  
Keyword(s):  
Crystalline Structures ◽  
Induced Changes

Small specimen techniques for estimation of tensile, fatigue, fracture and crack propagation material model parameters

2021 ◽  
pp. 030932472110252
Author(s):  
Julija Kazakeviciute ◽  
James Paul Rouse ◽  
Davide Focatiis ◽  
Christopher Hyde
Keyword(s):  
Fatigue Fracture ◽  
Structural Integrity ◽  
Standard Specimen ◽  
Creep Behaviour ◽  
Parameter Determination ◽  
Model Parameters ◽  
Small Specimen ◽  
Testing Methods ◽  
Advantages And Disadvantages ◽  
Tensile Fatigue

Small specimen mechanical testing is an exciting and rapidly developing field in which fundamental deformation behaviours can be observed from experiments performed on comparatively small amounts of material. These methods are particularly useful when there is limited source material to facilitate a sufficient number of standard specimen tests, if any at all. Such situations include the development of new materials or when performing routine maintenance/inspection studies of in-service components, requiring that material conditions are updated with service exposure. The potentially more challenging loading conditions and complex stress states experienced by small specimens, in comparison with standard specimen geometries, has led to a tendency for these methods to be used in ranking studies rather than for fundamental material parameter determination. Classifying a specimen as ‘small’ can be subjective, and in the present work the focus is to review testing methods that utilise specimens with characteristic dimensions of less than 50 mm. By doing this, observations made here will be relevant to industrial service monitoring problems, wherein small samples of material are extracted and tested from operational components in such a way that structural integrity is not compromised. Whilst recently the majority of small specimen test techniques development have focused on the determination of creep behaviour/properties as well as sub-size tensile testing, attention is given here to small specimen testing methods for determining specific tensile, fatigue, fracture and crack growth properties. These areas are currently underrepresented in published reviews. The suitability of specimens and methods is discussed here, along with associated advantages and disadvantages.

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