What is effective plastic strain in LS Dyna?
What is effective plastic strain in LS Dyna?
Effective plastic strain is a monotonically increasing scalar value which is calculated incrementally as a function of (Dp)ij, the plastic component of the rate of deformation tensor. In tensorial notation, this is expressed as… epspl=integral over time of (depspl)=integral[sqrt(2/3(Dp)ij*(Dp)ij)]*dt.
How do you calculate effective strain?
Effective strain, expressed in tensorial notation, is epseff = sqrt[ 2/3 (epsdev)ij (epsdev)ij ] where epsdev are deviatoric strains.
What is effective stress and effective strain?
The effective stress can be defined as the stress, depending on the applied tension and pore pressure , which controls the strain or strength behaviour of soil and rock (or a generic porous body) for whatever pore pressure value or, in other terms, the stress which applied over a dry porous body (i.e. at ) provides the …
What is equivalent plastic strain?
1. The critical equivalent plastic strain is obtained on the basis of the parameters of rock mechanics. 2. The pore pressure distribution p(r) is calculated using the flow equation. Bottomhole pressure is first assumed, and the pore pressure distribution is then obtained under the underbalance pressure assumed.
How do you calculate true plastic strain?
The plastic strain is obtained by subtracting the elastic strain, defined as the value of true stress divided by the Young’s modulus, from the value of total strain (see Figure 1).
How is Etan calculated?
Actually, this condition of E > Etan is ALWAYS met if a stress vs. epspl curve is given. For example, if Ep = 3253 and E were set to an extremely low value, say 10, Etan is then equal to Ep*E/(Ep + E) = 9.97 .
What is the unit for strain?
The unit for strain in the SI (Système International) is “one” i.e. 1 ε= 1 = 1 m/m. In practice, the “unit” for strain is called “strain” and the symbol e is used. Usually, strain is in the order of um/m, i.e. 10-6, and therefore, the unit “µε” (microstrain) is most commonly used.
What is seepage pressure?
Seepage Pressure : • The pressure exerted by water on the soil through which it percolates. Seepage pressure, w.
What are principal strains?
Principal Strain: Maximum and minimum normal strain possible for a specific point on a structural element. Shear strain is 0 at the orientation where principal strain occurs.
How do you calculate plastic strain ratio?
r = ew/et
- True width strain ew = ln(wf / wo)
- True thickness strain et = ln (tf / to)
- wf = Final width.
- wo = Original width.
- tf = Final thickness.
- to = Original thickness.
