Calculating Friction Force with Wedge Action Modeling

  • Thread starter Thread starter Simon666
  • Start date Start date
  • Tags Tags
    Modeling Wedge
AI Thread Summary
Calculating frictional forces in a mass spring model for yarn stuck between wedges presents challenges due to the zero-dimensional nature of nodes. A proposed solution involves assuming finite dimensions and using a penalty method to create a compressive force when the mass point approaches the wedge surfaces. The friction force is determined by multiplying the coefficient of friction by the total force vector, projected onto the symmetry plane of the wedge. While this approach is not entirely physically accurate, it offers a workable solution within the constraints of the model. Further insights or alternative methods to improve this approach are welcomed.
Simon666
Messages
93
Reaction score
0
Hi, kind of stuck with how to calculate frictional forces in a particular problem: I am modeling yarn using mass spring system, zero dimensional nodes. Question is, what to do when a yarn can get stuck between a wedge?

How to calculate friction force vector, surface reaction and so? Since a node is zero dimensional, seems kind of impossible. Maybe I need to assume kind of finite dimensions and work with some kind of penalty method penalizing the distance between a node and the surfaces of the wedge? Still, I am completely stuck...
 
Physics news on Phys.org
Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
 
I did not fully solve it, I managed to find a way around that is not physically 100% correct. Around my point mass, I started to look for wedge surfaces and if sum of the distances between mass point and the two wedge surfaces fell between some treshold, started generating penalizing compressive force, located along the normal on the symmetry plane between the wedge planes, and along a direction trying to put the mass point on the symmetry plane.

Friction force size is then mu times the total force vector on my mass point with the dot product of the normal on the symmetry plane of the wedge. Friction force direction is the projection of the total force vector on my mass point on the symmetry plane of the wedge, normalized and inverted.

It's not really correct but it's a mass spring model, I think it's the best I can do unless someone has a better idea.
 
Thread ''splain this hydrostatic paradox in tiny words'
This is (ostensibly) not a trick shot or video*. The scale was balanced before any blue water was added. 550mL of blue water was added to the left side. only 60mL of water needed to be added to the right side to re-balance the scale. Apparently, the scale will balance when the height of the two columns is equal. The left side of the scale only feels the weight of the column above the lower "tail" of the funnel (i.e. 60mL). So where does the weight of the remaining (550-60=) 490mL go...
Consider an extremely long and perfectly calibrated scale. A car with a mass of 1000 kg is placed on it, and the scale registers this weight accurately. Now, suppose the car begins to move, reaching very high speeds. Neglecting air resistance and rolling friction, if the car attains, for example, a velocity of 500 km/h, will the scale still indicate a weight corresponding to 1000 kg, or will the measured value decrease as a result of the motion? In a second scenario, imagine a person with a...
Scalar and vector potentials in Coulomb gauge Assume Coulomb gauge so that $$\nabla \cdot \mathbf{A}=0.\tag{1}$$ The scalar potential ##\phi## is described by Poisson's equation $$\nabla^2 \phi = -\frac{\rho}{\varepsilon_0}\tag{2}$$ which has the instantaneous general solution given by $$\phi(\mathbf{r},t)=\frac{1}{4\pi\varepsilon_0}\int \frac{\rho(\mathbf{r}',t)}{|\mathbf{r}-\mathbf{r}'|}d^3r'.\tag{3}$$ In Coulomb gauge the vector potential ##\mathbf{A}## is given by...
Back
Top