What is quasi-static analysis?

The quasi-static analysis considers the change of boundary conditions in terms of time, and can obtain the system or structure response under different external conditions. It is worth noting that quasi-static analysis ignores the effects of inertia, damping, and frequency.

What is quasi-static in mechanics?

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.

What is quasi-static acceleration?

In a static problem we assume acceleration is zero. Quasi-static means that at a given instant in time we can assume the problem is static. This assumption works well when inertial effects are very low.

What is dyna3d?

About. LS-DYNA is a general-purpose finite element program capable of simulating complex real world problems. It is used by the automobile, aerospace, construction, military, manufacturing, and bioengineering industries.

What are the characteristics of quasi static process?

A quasi static process is a thermodynamic process that happens slowly enough for the system to remain in internal equilibrium. An example of this is quasi-static compression, where the volume of a system changes at a slow rate enough to allow the pressure to remain uniform and constant throughout the system.

Why quasi static process is important?

This is crucial in order to have well-defined state variables such as the temperature or the pressure of the system, which are defined only for systems in equilibrium. Thus, if one pretends to track the value of these variables as one progresses along a thermodynamic process, the process needs to be quasi static.

Is quasi-static process isothermal?

An isothermal process studied in this chapter is quasi-statically performed, since to be isothermal throughout the change of volume, you must be able to state the temperature of the system at each step, which is possible only if the system is in thermal equilibrium continuously.

What is quasi-static strain rate?

Quasi-static indicates that the acceleration effect on load measuring devices is insignificant and the stress wave propagation in the test specimen need not be considered. The strain rate of typical quasi-static tensile tests is approximately 0.01 s-1 (1 s-1 = 100%/ second).

What is the difference between LS-DYNA and ANSYS?

ANSYS is a general purpose finite element code, typically used if a deformable part is not undergoing large rigid-body motions, but e.g. results with a high spatial resolution for stress or strain are desired. LS-DYNA is also a finite-element code, but with a particular emphasis on the explicit solver.

Who owns Nastran?

Nastran

Is reversible process quasi-static?

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.

Is adiabatic process quasi-static?

Adiabatic Processes In an adiabatic process, the system is insulated from its environment so that although the state of the system changes, no heat is allowed to enter or leave the system, as seen in Figure 3.5. 3. An adiabatic process can be conducted either quasi-statically or non-quasi-statically.

How are quasi static tests simulated in LS-DYNA?

Quasi-static tests that are part of the federal regulations such as FMVSS 216[1] and FMVSS 207/210[1] is predominantly simulated using LS-DYNA’sexplicit solver. To be able to produce results in a reasonable time, mass-scaling and time-scaling are employed for these simulations, thereby the physics of the problem gets compromised.

When was the implicit solver introduced in LS-DYNA?

An implicit solver with limited features was introduced in version 950, primarily aimed at solving spring-back problems as a complement to standard explicit forming simulations. Since then LS-DYNA Implicit has evolved to a complete product, covering many different disciplines in linear and nonlinear simulation technology.

Which is the latest example of LS-DYNA?

The latest examples were presented at the 2017 Salzburg conference by George Laird. Other recent input files were provided by Alexander Gromer of DYNAmore (2016 Bamberg) and by Satish Pathy of LSTC.

Can you use explicit dynamics to model quasi static events?

•Explicit dynamics solves for the state of dynamic equilibrium where inertia can play a dominant role in the solution. –Application of explicit dynamics to model quasi-static events requires special consideration: •It is computationally impractical to model the process in its natural time period.