2 votes

Dynamic forces in Simulink

The sign function gives zero friction force for zero velocity, which is generally not correct (and leads to the artificial oscillations, as the integrator is made for smooth systems and cannot handle ...
Dominik Kern's user avatar
2 votes
Accepted

Why Do the Fingers in Mechanical Pencils Fly Out?

The plastic fingers are moulded in the open position. During assembly and operation they are compressed. I imagine that the fingers are moulded so that with the ring in the position shown they are in ...
Transistor's user avatar
  • 10.7k
2 votes

How to calculate wind impact to DIY solar panel array frame?

From your units, I'm assuming you're based in the US ? Have a look at the skyciv online wind calculator : https://skyciv.com/wind-load-calculator/ It has support for sussing out wind loads to ASCE7-16....
Andorrax's user avatar
  • 144
2 votes
Accepted

How to calculate force acting on axle from hub motor with known torque?

Assuming the motor has a Torque of 40Nm, what is the force on the fork centred at the axle? Since the system is fixed in place, there is no acceleration or rotation. Therefore any torque developed ...
BowlOfRed's user avatar
  • 136
2 votes

A question on understanding the nature of static equilibrium

In Engineering, we are usually not concerned with the detailed molecular level of material behavior. That is the job of material scientists and engineers. We assume a point load on a slab or on top ...
kamran's user avatar
  • 22.4k
2 votes

Understanding the nature of Force and Moment FBD diagram

Premise When you analyze the equilibrium of a body you first have to be sure that it is in a static configuration. In other words, it's bound to enough external constraints such that the reaction ...
RocketScience's user avatar
1 vote
Accepted

How do I relate tongue weight to weight x distance?

you need to jack up the car and check the structural layout of the hitch. Usually, there are two arms welded to the sides of the hitch receptor reaching to the left and right side of the mainframe of ...
kamran's user avatar
  • 22.4k
1 vote

Calculating forces of TV wall mount with long extended arm. Need help with Physics, torque vs force and anchor requirements

The important thing here is taking into account the dynamic load on the mount. Such as the impact of the vibration of banging a door or swinging the TV bracket into a new position. A dynamic load ...
kamran's user avatar
  • 22.4k
1 vote

A question on understanding the nature of static equilibrium

What you describe in your first example is perfectly covered by usual engineering calculations and is described by the Poisson effect. When you squish a solid (in this case, by its own weight) said ...
Zegpi's user avatar
  • 151
1 vote

How to calculate stiffness to weight ratio of one big tube vs two small tubes (see drawing)?

Caveat: I asked the question and give an answer here myself that takes the specific numbers given in my question and applies them to the formulas in the answer given by Tomas Letal. I do not have the ...
aehhhhmm's user avatar
1 vote

How to calculate stiffness to weight ratio of one big tube vs two small tubes (see drawing)?

Lateral stiffness Assuming the plates stay parallel, you can use lateral deflection of beam end while keeping the 0 rotation there. Replacing one of the plates with a force-moment couple, $F_1$ and $...
Tomáš Létal's user avatar
1 vote
Accepted

How to calculate the mechanical advantage of torque reaction arms (or balanced articulated arms)?

In each joint, The moments are the weight of the load plus the weight of the lift arm(s) multiplied by the distance to the joint. setting the moments sum about the joint equal to zero will give ...
kamran's user avatar
  • 22.4k
1 vote

How to calculate the volume of a partially submerged horizontal cylinder and the center of buoyancy?

Assuming balanced loading, meaning the results of the load placed on the buoy and its weight are passing through the CG of the buoy the 4 cylinders are submerged equally to a depth of H such that the ...
kamran's user avatar
  • 22.4k
1 vote

Pull out force for a 5/8" tapped bolt

Short Answer: 12,000 lb and not necessarily Long Answer: For a rough estimation, let's say you are using a grade 5 bolt and A500 grB tubing, and let's assume your thread engagement length is 1/4"....
Scott Weiss's user avatar
1 vote
Accepted

How to calculate forces on bearings in a chain drive

Assuming the shaft and sprocket masses are small and performing static analysis: If you have an output torque $T_\text{out}$ on the output shaft, and the sprocket diameter is $d$ then chain force $F_\...
drC1Ron's user avatar
  • 411
1 vote

Distributing force over multiple springs evenly

The only very simple mechanism to do this is a post in a hole, which naturally leads you to using one spring (which must be cheaper than 4, Shirley). Otherwise you can try to fab a parallel motion ...
Greg Locock's user avatar
1 vote
Accepted

Finding hoop stress in a half-cylinder

The sketch above forms the base for solving reactions at "a" and "b". Note that if the loads are acting on the near edge, then there is a twisting need to be considered. Without ...
r13's user avatar
  • 8,194
1 vote
Accepted

Angle of attack for torque calculation from buoyancy force

you should use angle 2. The buoyancy in this case is due to pressure from 3 sides. the 2 lateral sides undergo triangular pressure distribution that opposes each other and cancels. Therefore the only ...
kamran's user avatar
  • 22.4k
1 vote

Dynamic forces in Simulink

This is how it (time stepping, an alternative to event-detection algorithms) can be done in Python (I am afraid having neither SimuLink nor MatLab at hand, but the algorithm should become clear) ...
Dominik Kern's user avatar
1 vote

I am designing a light that is hung from the end of an arm. How do I calculate the amount of force on the fastener where the arm attaches to the wall

Say the arm is 2 inches vertically at the base where it is hung by the fastener and the distance between the fastener and the point of pressure is 1.5 inches. $$F_{fastener}=\frac{8lbs*27in}{1.5in}=...
kamran's user avatar
  • 22.4k
1 vote
Accepted

I am designing a light that is hung from the end of an arm. How do I calculate the amount of force on the fastener where the arm attaches to the wall

Convert mass and radius to Torque. The force would be distributed between fastener wall contact areas unevenly with very high pressure on the bottom edge puncturing the wall with the same torque but ...
Tony Stewart EE75's user avatar
1 vote
Accepted

Calculate uphill efficiency on different gears

You found that the total energy needed to climb the hill is the same despite using two different gear ratios. This is in fact correct because of conservation of energy. Look at is from another point ...
ArC 99's user avatar
  • 81
1 vote

Force required for a power generator in a coal power station

It is common practice to "motor" a turbine/generator assembly slowly in the absence of steam or water flow, while maintaining full lubricating oil pressure, so the sheer weight of the blade ...
niels nielsen's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible