scholarly journals Development of a novel mechanical tester for microfracture analysis

2017 ◽  
Vol 13 (4-2) ◽  
pp. 470-476
Author(s):  
Kheng Lim Goh ◽  
Ye Seng Chen ◽  
Roy Jia Jun Chua ◽  
Tze Chow Fong ◽  
Yu Ker Woh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Testing ◽  
Test Specimen ◽  
Soft Materials ◽  
Biological Tissues ◽  
Test Procedures ◽  
Coir Fibre ◽  
Recent Advancement ◽  
Properties Of Materials ◽  
Microscopic Deformation

The study of the mechanical properties of materials is important in the design and fabrication of any microscale product. Acquiring information such as the fracture toughness, fatigue limits, ultimate tensile and yield strength of these materials would help to determine the reliability of the final product made using the material. Traditionally, these material properties are obtained via mechanical testing on a macroscale tester such as the machines produced by Instron. However, mechanical testing of ‘softer’ materials with a microscopic size is more complicated as the test procedures and equipment have to address concerns such as clamping and alignment of specimen. Recent advancement in micromachining and micro-manufacturing has resulted in the availability of advanced and affordable instrumentation that can be applied to precisely manipulate the materials at microscopic dimensions; this provides the impetus to the development of microscale mechanical testers to study the micro-elasticity and micro-fracture mechanics of soft materials. The focus of this report is on the development of a micromechanical tester that can be used to study micrometer thick biomaterials and biological tissues. The tester can be mounted onto an X-Y stage of an inverted or compound microscope to observe the microscopic deformation and microfracture of the test specimen during testing. Three case studies are presented here to illustrate the performance of the mechanical tester. These studies address the characterisation of the mechanical properties of the flax fibre, oil palm empty fruit bunch fibre and coir fibre in dry and wet states.

scholarly journals Image-based analysis of uniaxial ring test for mechanical characterization of soft materials and biological tissues

Soft Matter ◽  
2019 ◽  
Vol 15 (16) ◽  
pp. 3353-3361 ◽  
Author(s):  
Eline E. van Haaften ◽  
Mark C. van Turnhout ◽  
Nicholas A. Kurniawan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characterization ◽  
Soft Materials ◽  
Biological Tissues ◽  
Ring Test ◽  
Analysis Approach

We propose a simple image-based analysis approach to accurately estimate the mechanical properties of ring-shaped materials.

Application of Small Punch Tests for Screening of Mechanical Properties for T91 Steel

2014 ◽  
Vol 606 ◽  
pp. 43-46
Author(s):  
Michal Lašan
Keyword(s):  
Mechanical Properties ◽  
Test Specimen ◽  
Deformation Energy ◽  
Operating Conditions ◽  
Test Material ◽  
Small Punch Test ◽  
Test Procedures ◽  
Small Punch ◽  
Punch Test ◽  
Gen Iv

The T91 steel is considered a perspective structural material for Generation IV (GEN IV) nuclear reactors components. The operating conditions of GEN IV nuclear reactor, which include higher operating temperatures, higher neutron fluencies and using liquid metals as coolants, constitute new challenges for structural materials validation. To properly assess the impact of radiation, thermal, load and environmental damage the screening test procedures for initial overview of the induced changes of mechanical properties need to be developed and validated. One of the test procedures with potential to be used for the mechanical properties screening is Small Punch test. Small Punch test receive considerable attention since their development in the 1980's. The use of miniaturized test specimen constitutes minimal requirements for the test material and the option of obtaining the test material directly from the component. They have been successfully used on industrial scale for design life extension of components for energy industry in the past. In this paper we address the issue of the Fracture Appearance Transition Temperature (FATT) determination by the means of Small Punch test for the T91 steel, manufactured according to ASTM standard A387-Ed99. The test specimen were manufactured and used for the experiments in a wide range of test temperatures. Multiple levels of deformation energy were used to provide more representative interpretation of the test data. A data fit is applied on the deformation energy – test temperature dependence to obtain the value of FATT from Small Punch test, which is subsequently correlated to the values obtained from testing sub-size Charpy specimens.

scholarly journals Determination by Relaxation Tests of the Mechanical Properties of Soft Polyacrylamide Gels Made for Mechanobiology Studies

2021 ◽  
Author(s):  
Daniel Pérez-Calixto ◽  
Samuel Amat-Shapiro ◽  
Diego Zamarrón-Hernández ◽  
Genaro Vázquez-Victorio ◽  
Pierre-Henri Puech ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Materials Science ◽  
Chemical Properties ◽  
Soft Materials ◽  
Maxwell Model ◽  
Biological Tissues ◽  
Elastic Stiffness ◽  
Critical Signal ◽  
Compliant Substrates

Following the general aim of recapitulating the native mechanical properties of tissues and organs in vitro, the field of materials science and engineering has benefited from recent progress in developing compliant substrates with similar physical and chemical properties. In particular, in the field of mechanobiology, soft hydrogels can now reproduce the precise range of stiffnesses of healthy and pathological tissues to study the mechanisms behind cell response to mechanics. However, it was shown that biological tissues are not only elastic but also relax at different timescales. Cells can indeed perceive and actually need this dissipation because it is a critical signal integrated with other signals to define adhesion, spreading and even more complicated functions. The mechanical definition of hydrogels used in mechanobiology is however commonly limited to the elastic stiffness (Young’s modulus) and this value is known to depend greatly on the measurement conditions that are rarely reported. Here, we report that a simple relaxation test performed under well defined conditions can provide all the necessary information to characterize soft materials mechanically, by fitting the dissipation behavior with a generalized Maxwell model (GMM). The method was validated using soft polyacrylamide hydrogels and proved to be very useful to unveil precise mechanical properties of gels that cells can sense and offer a set of characteristic values that can be compared with what is typically reported from microindentation tests.

scholarly journals Determination by Relaxation Tests of the Mechanical Properties of Soft Polyacrylamide Gels Made for Mechanobiology Studies

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 629
Author(s):  
Daniel Pérez-Calixto ◽  
Samuel Amat-Shapiro ◽  
Diego Zamarrón-Hernández ◽  
Genaro Vázquez-Victorio ◽  
Pierre-Henri Puech ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Materials Science ◽  
Chemical Properties ◽  
Soft Materials ◽  
Maxwell Model ◽  
Biological Tissues ◽  
Elastic Stiffness ◽  
Critical Signal ◽  
Simple Method

Following the general aim of recapitulating the native mechanical properties of tissues and organs in vitro, the field of materials science and engineering has benefited from recent progress in developing compliant substrates with physical and chemical properties similar to those of biological materials. In particular, in the field of mechanobiology, soft hydrogels can now reproduce the precise range of stiffnesses of healthy and pathological tissues to study the mechanisms behind cell responses to mechanics. However, it was shown that biological tissues are not only elastic but also relax at different timescales. Cells can, indeed, perceive this dissipation and actually need it because it is a critical signal integrated with other signals to define adhesion, spreading and even more complicated functions. The mechanical characterization of hydrogels used in mechanobiology is, however, commonly limited to the elastic stiffness (Young’s modulus) and this value is known to depend greatly on the measurement conditions that are rarely reported in great detail. Here, we report that a simple relaxation test performed under well-defined conditions can provide all the necessary information for characterizing soft materials mechanically, by fitting the dissipation behavior with a generalized Maxwell model (GMM). The simple method was validated using soft polyacrylamide hydrogels and proved to be very useful to readily unveil precise mechanical properties of gels that cells can sense and offer a set of characteristic values that can be compared with what is typically reported from microindentation tests.

LABORATORY TESTS OF THE PHYSICAL-MECHANICAL PROPERTIES OF MATERIALS FOR REMEDIAL JOBS

2020 ◽  
pp. 58-63
Author(s):  
M.A. Druzhinin ◽  
◽  
G.V. Okromelidze ◽  
O.V. Garshina ◽  
I.A. Kudimov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Mechanical Properties Of Materials ◽  
Properties Of Materials

scholarly journals Depth-Sensing Indentation as a Micro- and Nanomechanical Approach to Characterisation of Mechanical Properties of Soft, Biological, and Biomimetic Materials

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 15 ◽  
Author(s):  
Nikolay V. Perepelkin ◽  
Feodor M. Borodich ◽  
Alexander E. Kovalev ◽  
Stanislav N. Gorb
Keyword(s):  
Review Paper ◽  
Soft Materials ◽  
Data Fitting ◽  
Depth Sensing ◽  
Adhesive Properties ◽  
Distinctive Features ◽  
Experimental Part ◽  
Properties Of Materials ◽  
The Mathematical Model ◽  
Non Destructive

Classical methods of material testing become extremely complicated or impossible at micro-/nanoscale. At the same time, depth-sensing indentation (DSI) can be applied without much change at various length scales. However, interpretation of the DSI data needs to be done carefully, as length-scale dependent effects, such as adhesion, should be taken into account. This review paper is focused on different DSI approaches and factors that can lead to erroneous results, if conventional DSI methods are used for micro-/nanomechanical testing, or testing soft materials. We also review our recent advances in the development of a method that intrinsically takes adhesion effects in DSI into account: the Borodich–Galanov (BG) method, and its extended variant (eBG). The BG/eBG methods can be considered a framework made of the experimental part (DSI by means of spherical indenters), and the data processing part (data fitting based on the mathematical model of the experiment), with such distinctive features as intrinsic model-based account of adhesion, the ability to simultaneously estimate elastic and adhesive properties of materials, and non-destructive nature.

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