I am simulating a dropping object that falls under gravity force into a liquid domain. But when I add mass scaling, the gravity forces (applied via Gravity load in abaqus) do not seem to work and the object either doesn't fall or falls too slowly. Apparently when I apply a mass scaling with a factor of X, the gravity force scales down by a factor of 1/X. Is this correct and is there any way to deal with this problem without changing the gravitational acceleration?
According to Abaqus manual (sect. 11.6.1 MASS SCALING: When mass scaling is or is not used), gravity loads are not affected by mass scaling. In other words, ρ·g=ρ0·g0, where ρ0 and g0 are initial material density and gravitational acceleration, respectively. Therefore, gravitational acceleration after mass scaling should be corrected as g=g0*ρ0/ρ.
usting Concrete Water Content
Why we need to adjustment of water with concrete
Adjusting the water content in concrete is important because it affects the strength and workability of the finished product. If too much water is added to the mix, the concrete will be more workable, but it will also be weaker and more susceptible to shrinkage and cracking. If too little water is added, the concrete will be less workable, but it will also be stronger and more durable. The correct amount of water is determined by the desired strength and workability of the concrete, as well as the type of aggregate and the environmental conditions in which the concrete will be placed.
Does mass scaling affect the gravity forces in Abaqus
Yes, mass scaling in Abaqus can affect the gravity forces applied to a model.
In Abaqus, gravity is typically applied as a load on the model, and is defined by a vector with a magnitude and direction. The magnitude of the gravity vector is typically defined as 9.81 m/s^2, which is the acceleration due to gravity on the surface of the Earth. However, if the mass of the model is scaled, the magnitude of the gravity vector will also be scaled by the same factor. This can lead to unrealistic results, if the mass scaling is not taken into account when defining the gravity load.
To avoid this problem, it is recommended to use non-dimensional parameter such as Froude number or Weber number to analyze the gravity effect instead of scaling the gravity vector
Thanks for your answer Victor. Does Abaqus correct the g automatically or it should be done manually? Based on my experience it is not done automatically.
Ali Jafari Yes, mentioned correction of gravitational acceleration should be done manually.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Inorganic Materials
- Metals
- Alloys
- Steel