Deriving displacement tensor from Hencky (true) strain tensor
Jul 12, 2024 · The Hencky strain, AKA true strain, logarithmic strain, can be related to displacement tensor as follows: $$ E = ln(U) $$ However, Hencky strain is typically done only for principal strains. This can be easily shown by actually trying to calculate the full displacement tensor using the above...
Beginner's question on Stress-strain curve - Physics Forums
Jul 6, 2011 · However, in a true curve, the instantaneous cross-sectional area is used, so there is a continuous rise until failure. The decrease in slope after the yield point is due to weaker inter-molecular forces, and there is still a sudden bend in the true stress-true strain curve due to the area being almost the same as the initial area at the yield ...
Why true strain is always smaller than nominal strain in tensile test?
Aug 10, 2019 · True strain takes into account the change in cross-sectional area of the material during the deformation process, while nominal strain only considers the original cross-sectional area. This means that true strain is a more accurate measure of …
Strength Coefficient and Strain-Hardening Exponent - Physics …
Aug 28, 2006 · - True strain is ln (L2/L0) = ln (3.2/2.0) = ln 1.6 = .47 *So we now have two points on our true stress-strain curve: (.22, 30000) and (.47, 44800). The book plots these points using a log scale and then finds the slope to determine the strain hardening exponent.
Why calculate true stress and strain? - Physics Forums
Mar 17, 2012 · However, the method of calculating true stress/strain may differ depending on the material's properties and behavior under load. How is true stress/strain measured in experiments? True stress/strain can be measured in experiments by using specialized equipment, such as a universal testing machine, which applies a controlled load to a material ...
Strain hardening exponent Question - Physics Forums
Oct 15, 2014 · The pure elastic strain stops at the proportional limit. In the elastic range, Hooke's law describes the relationship between stress and strain, namely σ = E ε, where E is the elastic modulus. I have seen reference to the Hollomon equation, given by σ = K ε n, where ε is described as the true strain or true plastic strain. Depending on ...
Calculating Nominal strain at which Necking Occurs - Physics …
Jan 13, 2010 · In summary, the conversation discusses using the given data on two wires of different gauge lengths and their behavior under tension to calculate the nominal strain at which necking begins. The relevant equations and concepts relating to necking, stress/strain, and true stress/strain are also mentioned.
Same E for true stress true strain? - Physics Forums
Nov 26, 2014 · No, true stress and true strain cannot be directly measured as they require knowledge of the actual cross-sectional area and length of the material, which can change during the test. They are instead calculated using engineering stress and strain values. What are the limitations of using true stress and true strain? One limitation is that true ...
True Stress-Strain Curve on the Log Scale: Which portion is the …
Nov 17, 2012 · How does the plastic region affect the overall shape of the True Stress-Strain Curve? The plastic region can significantly influence the overall shape of the True Stress-Strain Curve. A larger plastic region will result in a curve with a more gradual slope, indicating a material's ability to withstand greater amounts of stress before breaking.
How is the UTS different from breaking stress and why? - Physics …
May 27, 2015 · There is an engineering stress strain curve and a true stress strain curve. The engineering stress strain curve assumes that the member cross section area remains constant at all levels of tensile load, but in actuality, cross section starts to significantly reduce (called necking) at high stress values beyond the yield point, in which case if you plot true stress, …