#elastic modulus

[the-chemistry-side-of]

Deformation of Matter

A few different forms of deforming solids explained.

While solids do have a definite shape and volume, they can be deformed to take a different shape. Think of sculpting clay or blowing glass. A force needs to be applied at the correct conditions for this to happen. When there is a force that is applied perpendicular to a surface, this is called strain. Strain is more technically the amount of deformation and is proportional to the stress applied…

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[ijtsrd]

Multiscale Modeling Approach for Prediction the Elastic Modulus of Percolated Cellulose Nanocrystal CNC Network

by Mehrdad Bor | Jim Huang ""Multiscale Modeling Approach for Prediction the Elastic Modulus of Percolated Cellulose Nanocrystal (CNC) Network""

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019,

URL: https://www.ijtsrd.com/papers/ijtsrd26553.pdf  

Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/26553/multiscale-modeling-approach-for-prediction-the-elastic-modulus-of-percolated-cellulose-nanocrystal-cnc-network/mehrdad-bor

review papers, call for paper social science

In this study the effective elastic modulus of cellulose nanocrystal CNC network is evaluated using multiscale method and micromechanical analysis. For this purpose, the elastic modulus of CNC water phases are randomly assigned to a two dimensional 2D checkerboard structure and the elastic response is evaluated. In addition, the effect of having a different number of phases CNC, water and interface is evaluated by assigning a discreet and continuous distribution of elastic modulus to checkerboard structure. When the number of phases increases dramatically, the distribution of phases is continuous and is defined with Weibull distribution. The results show that for two phase materials CNC and water when the microstructure has organized pattern the rule of the mixture and numerical model provide the same effective modulus, however when the microstructure is completely random, the self consistent micromechanical model should be used. Also, this study suggests 50 volume fraction as the percolation threshold for the CNC network with 10 GPa effective elastic modulus. The results from percolated multiphase network reveal that for microstructures with 4 phases and above, the percolated network converge to 35 GPa. 

[innovation-in-polyurethanes]

Fiber Reinforced TPU Composites

Fiber Reinforced TPU Composites

Patent Title: THERMOPLASTIC POLYURETHANE MATRIX RESIN

 Number/Link: WO 2018/104145

Applicant/Assignee:  Henkel

Publication date: 14 June 2018

“Gist”: TPU based on a vicinal alkane diol together with an alkoxylated aromatic diol can be used as matrix material in a fiber composite

Why it is interesting: According to this invention a thermoplastic polyurethane with a high Tg (pref. >80°C) and a high…

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[scienceandfood]

DIY Kitchen Science: Perfectly Unsoggy Apple Pie

If you've baked an apple pie, you have probably encountered the dreaded problem of a soggy pie crust. At this year's Science of Pie event, the student scientists of Team On the Road sought to solve this pie-baking mishap by determining the optimal apple slice thickness; the idea was that apple slices of varying thickness would release different  amounts of water when baked, with more water released giving rise to a soggy crust. Read more...

Photo Courtesy: (A) & (B): Patrick Tran, (C): Team on the Road

[nottinghamengineeringstude-blog1]

Stiffness: Part 9 Stiffness in Different Materials

Elastic Modulus increases as Bond stiffness increases. Eg, when equilibrium bond length decreases = strong bonding. And small atoms and closer packed structures.

Ceramics = very strong bonding and high stiffness

Metals = strong bonding and close packed structures, intermediate stiffness

Polymers = weak bonding and open structures, lowest stiffness.

Can we make materials stiffer?

Yes, but only through producing composite materials

We can't change the bond strength or spacing by alloying

Can mix together materials of a different stiffness to give varying results

Eg, fibre glass in a polymer matrix, or ceramic fibres in a metal matrix

Application of the Elastic Modulus

Allows the behaviour of a material under load to be predicted - only applicable when the load produces reversible elastic deformation.

Can predict elastic extension of a cable in tension, and the deflection of a beam in bending

Materials with a higher stiffness will extend or deflect less - steel < aluminium < wood

Determine the energy stored in a structure that has been elastically deformed - such as a spring

In the case of loading to a given stress, a low stiffness is more desirable.

[nottinghamengineeringstude-blog1]

Stiffness: Part 6 Bonding I

In order to understand the Elastic Modulus we must

Look at the structure of materials and the nature of the forces that are holding them together.

Examine the way in which atoms are packed together.

Bonding and Stiffness

Atoms in crystals are held together by bonds which resemble springs

The forces between the atoms depend on the bond strength and separation.

The way atoms are packed into the crystals determines how many bonds per unit area hold the material together.

Stronger bonds, and more of them, give a higher stiffness.

Properties from Bonding - images shown on next post

The Elastic Modulus increases as Bond Stiffness.