What is mass scaling in FEA?

Mass-scaling refers to a technique whereby nonphysical mass is added to a structure in order to achieve a larger explicit timestep. You may have to reduce or eliminate mass scaling in a second run to gage the sensitivity of the results to the amount of mass added.

How do you change the scale factor in Abaqus?

Scaling deformations

  1. From the main menu bar, select OptionsCommon. Click the Basic tab in the dialog box that appears.
  2. Choose one of the following scale factor options:
  3. Click Apply to implement your changes.

What is time scaling factor in Abaqus?

According to abaqus help, time scaling factor is acceptable for explicit analysis if kinetic energy is one-tenth(0.1) of total energy in job results table. thus you have to increase the time scaling factor until error in job.

How do you do quasi-static analysis in Abaqus?

Quasi-static analyses can also be conducted in Abaqus/Standard. Quasi-static stress analysis in Abaqus/Standard is used to analyze linear or nonlinear problems with time-dependent material response (creep, swelling, viscoelasticity, and two-layer viscoplasticity) when inertia effects can be neglected.

How do you add mass scaling in Abaqus?

Defining a desired element-by-element stable time increment. You can define a desired element-by-element stable time increment for an element set for fixed or variable mass scaling. Abaqus/Explicit will then determine the necessary mass scaling factors.

What is deformation scale?

The deformation scale refers to the scale factor that the program uses to scale the deformed shape of the model. A larger deformation scale factor helps you visualize deflections that are a lot smaller compared to the original dimensions of the model.

How do I change the deformation scale factor in Ansys?

Deformation Scale Factor

  1. Click the Deformation Scale Factor icon in the bottom toolbar. The Deformation Scale Factor dialog box is displayed.
  2. Enter 100mm as Maximum displacement new value in the Deform Window dialog box.
  3. Click OK to exit the Deformation Scale Factor dialog box.

Which of the following is an example of time scaling?

Explanation: Time scaling is an example for operations performed on independent variable time. It is given by y (t) = x (at). Explanation: By comparing the given equation with y (t) = x (at) we get a=2. If a>1 then it is compressed version of x (t).

What’s the difference between quasi-static and dynamic analysis?

Quasi-static load means the load is applied so slowly that the structure deforms also very slowly (very low strain rate) and therefore the inertia force is very small and can be ignored. A dynamic load, on the other hand, casues a structure to vibrate and the inertia force is big enough and must be considered.

Is quasi-static process reversible?

Quasi-static processes are not reversible when sliding friction forces are present. An example is considered consisting of a cylinder containing a gas and equipped with a piston for which sliding friction forces are significant.

How do you calculate mass scale in Abaqus?

An alternative method of scaling the masses of elements in elset1 is to assign a stable time increment to them and allow Abaqus/Explicit to determine the mass scaling factors. The first fixed mass scaling definition scales the masses in the entire model by a factor of 50.

When to use mass scaling or time scaling in Abaqus?

As mentioned above, with all mass-scaling you need to keep an eye on your kinetic energies; as too much mass scaling will effect the physics of your problem. In explicit integration, the time incrementation depends on the size mesh, material density, and young modulus.

How is mass scaling used in dynamic analysis?

Mass scaling is often used in ABAQUS/Explicit for computational efficiency in quasi-static analyses and in some dynamic analyses that contain a few very small elements that control the stable time increment. Mass scaling can be used to: scale the mass of the entire model or scale the masses of individual elements and/or element sets;

What should mass scaling factor be for quasi static analysis?

Assume that for a quasi-static analysis a mass scaling factor of 50 is applied to all the elements in the model. Furthermore, assume that even after being scaled by a factor of 50, a few extremely small or poorly shaped elements are causing the stable time increment to be less than a desired minimum.

How does an explicit integration scheme work in Abaqus?

The explicit integration scheme in Abaqus/Explicit requires nodal mass or inertia to exist at all activated degrees of freedom (see Conventions ) unless constraints are applied using boundary conditions.

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