# Questions tagged [statics]

Statics is branch of engineering concerned with the analysis of forces and moments on physical systems in static equilibrium.

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I worry my diagram bending moment or Shear Force Diagram I have drawn is wrong So I have problem like the picture no.1 show and have solved then get reaction support (Ray & Rby) on The picture no....
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### Comparing reactor volume to achieve 95% efficiency for a CSTR and a PFR

Compare the reactor volume required to achieve 95% efficiency for a CSTR and a PFR for the following conditions: steady state, first-order reaction, flow rate =14 m^3/d and a reaction rate coefficient ...
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### Engineering Statics

I have attached an image of the question (both parts). In part (a), I found the tension in both cables but could not find the force in the tower AO. I also need help with part (b). Thank you!
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### Why do period and damping ratio affect acceleration?

In the table above, the period of the structure $(T)$, the acceleration coefficient on the structure ($g$ in terms of gravitational acceleration) $Sa(T)$, The damping ratio is expressed as $ζ$ . As ...
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Hi Please help me answer my homework about simplifying load diagrams quickly, Thanks. I don't know how to simplify the left-hand side but on the Right-hand side I'm guessing I have to move that 5 ft/...
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### Constructive examples for heat transfer into pivoted components

Hello fellow engineers, i have a question for anyone who knows about the constructive elements of wind power plants. In certain wind power plants there is a rotor lockout disk (see picture), where the ...
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### Do tensile and compressive stresses create moments?

Below are 3 examples I designed. My question is about the tensile and compressive stresses that occur in 3 examples under the influence of a horizontal force F=100N (earthquake force). I ask my ...
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### Can't find correct reaction loads for statically indeterminate problem

been working on this problem all day and I feel as if I am going crazy. I am using SkyCiv to confirm the right answer and cannot get close to it, I have messed up both my attempts at superimposing and ...
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### Why don't we calculate buckling in composite beams?

I have a frame, it consists of steel beams and my flooring is a composite deck. It consists of composite beams that are hinged to my steel frame beams. Composite beams do not transfer moments. Now, ...
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### How does a church built from stones survive 70 years under water?

Following the recent news about the Sau reservoir in Spain, the draught revealed an 11-century stone church which has been under water for 70 years since 1962 when the reservoir was built. How is it ...
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### Is there explicit expersion for the natural frequency of a cantilever timoshenko beam?

I am trying to find a closed form solution for the natural frequency of cantilever Timoshenko beam. In mechanical vibration (Rao, 5th edition) he outlined the details to include the Effects of Rotary ...
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### Equivalent system for a shaft driven by a belt

I have a pulley, rigidly connected to a shaft (supported by bearings which don't restrict rotation about x), which is driven by an input pulley of the same dimensions through a belt drive. Forces are ...
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### Shape of a beam that is bowed under compression?

Suppose you have a uniform beam, such as a piece of plywood that is 4 feet long, six inches wide, and half an inch thick. Suppose you cause it to bend by attaching, for example, a string under ...
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### Twisting of thick ring due to internal pressure

I have an axisymmetrical part that is subject to an internal (non-constant along the inner border, but constant in time) pressure (among other loads, but this is the one I am interested about) and I ...
1 vote
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### Static analysis of a lead screw and disc friction

I'm doing a static analysis of a square thread lead screw. I think this site gives a good description of the problem. Screw threads statics To calculate the moment on the thread the mean radius of ...
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### How to compute the torques of a network of rotating objects with cycles?

I am trying to figure out how to compute torques in a network of rotating objects. I assume that each object has a given moment of inertia, and some objects are accelerated by external means. The ...
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If we take the moment about A from the $F_{BC}$ will make the body want to rotate counter clock wise but If we take it from the point C it will make the body rotate clock wise whats the mistake?
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### Can Weibull Analysis be applied on random sample data?

I'm dealing with a sample on which I want to perform a Weibull analysis to get the median time to failure. The samples vary more or less continuously in their age as shown in the plot. Is the type of ...
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### Static problem with multiple trig terms, one variable

I've encountered an equation that origins from a mechanical static problem containing a spring. I think the simplest formulation is the following: $$(a- \sqrt{b-c*cos(x)})*cos(d-x) = e*cos(f+x)$$ ...
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### homework : torsors of constraints: Coulomb's laws

Bonjour , j’ai un devoir maison sur les torseurs mécaniques en lien avec la loi de Coulomb et Statiquecet je n’arrive pas à résoudre! Pouvez-vous m’aider s’il vous plaît?! Je met le sujet en photo ...
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### what are the compression forces in a strut if the strut is fixed

i am trying to match an experiment i have done and i dont know how to compute the force in the strut in terms of F given these boundary conditions. i have attempted to use fixed end moment equations ...
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### How do I electrically charge a sheet of plastic strongly enough that it firmly sticks to the wall?

electrostatic whiteboards I have a bunch of these special dry erase sheets. Someone gave them to me as a gift about a year ago; I see they are still available for purchase on the Internet — you can ...
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### The triangle of forces - Lami's rule

Hello there, In this question, I have to draw the shape so that I can solve the problem. I looked at the answer book and did not understand how to draw it. Can someone help me? Note that the answer is ...
1 vote
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### Self Locking Brake Question

I've been staring at this problem for statics for quite a while now and I just don't understand it. The question states: "The brake is to be designed to be self locking, that is, it will not ...
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### Unexpected inconsistency in modelling of load propagation in Icosahedron struts

My intent is to build a program dedicated to analysis of geodesic structures. My proof-of-concept spreadsheet is intended to help me clarify the interactions at each node, so that when I approach the ...
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### Trying to define proof-of-concept for structural analysis of geodesic grid

I would like to create a spreadsheet as a "proof-of-concept" for clarifying the relationships and equations involved in doing the structural analysis of a geodesic dome. I then plan to ...
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### Calculating forces of TV wall mount with long extended arm. Need help with Physics, torque vs force and anchor requirements

I'm planning to install a wall-mounted TV with a very long arm on a plasterboard wall, although conventional wisdom advises against it. The TV mount is 45cm wide with holes for 6 screws. To address my ...
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1 vote
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### Is there an equivalent of node voltage analysis in mechanical and civil engineering?

When analyzing the behavior of an electrical circuit, the core of the work often involves performing node voltage analysis. This allows you to determine voltage drops and currents of interest in the ...
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1 vote
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### Finite Element Method for Spherical Objects

I am familiar with the procedure of the FEM for simple planar objects like truss and etc. but my question would be whether it would be possible to use this method to calculate the stiffness or ...
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### What are the change in forces with a ribbon under tension is twisted?

Consider pallet strapping. It has width W. When the strap is flat, it has some maximum breaking strength B. Now, let's put one twist in it over X feet. Mentally we have a VERY skinny isoceles ...
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### How to I calculate the load on a webbing triple slide buckle?

I'm trying to figure out if this is a suitable way to create connection loops for a trampoline web. The first pic is a fairly standard black nylon slide. The rough middle bar increases friction. In ...
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### Statics projection/vectors problem

For the life of me I cannot understand part B. What does F(BA) and the 60 degree angle have to do with the projection of 500# on AC? Why can we just assume that the angle at C is 180-(45+60)? Thanks
1 vote
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### What is the moment of inertia of a circular segment?

Hi I read this response but it isn't exactly my situation I have a circle where the axis of rotation is on the c axis like this for a segment equal to the green. Specifically, I have a round steel ...
1 vote
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### Extension of a cantilever beam composed of unbonded layers

The question of the magnitude of the vertical deflection of a cantilever beam composed of unbonded layers has been posted here, but I was wondering if there is an analytical way to solve for the end ...
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### Moment of Inertia Problem

Im currently studying for the FE exam and I came across a problem from a FE practice test that I'm confused on. The specific question is on the parallel axis theorem of a trapezoid and the D value ...
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### Frames and Statics Question

this is an image describing an exam question I have to practice on, and I am so stuck.
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### Load distribution for a load centered over the length of the middle joist in a 3-joist system

I'm not an engineer, but I'm trying to understand the correct analysis for what seems like a pretty simple case. I'd like to know what the effective load on the middle joist is. ...
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### Laying problem in designing axis points in static design?

First of all, there is a simple pattern plan on the halter. Here, we design an axis point passing through the midpoints of the columns and use it in the static calculation program. However, when we do ...
1 vote
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### A question on understanding the nature of static equilibrium

In the statics lesson, we do not think about the effects of forces on objects. In other words, we do not assume that an object can break, bend or twist. In the same situation, we can combine different ...
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### Understanding the nature of Force and Moment FBD diagram

Hello, I am Civil engineer Bilgehan Yılmaz. First of all, I would like to ask a question about basic statics, I modelled my question below. The following forces are applied around a wooden stick with ...
1 vote
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### Are the compressive and tensile stresses in the beams always equal?

If we examine the $example-1$ of cantilever beam 1 above, there will be shear force $Ft$ and moment $M$ that will keep the beam in balance statically. However, when we examine the strength, that is, ...
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### Distributed load on a slope/axle

In statics they teach you about distributed beams, how to calculate the total force, the engagement point, etc. I can't find any information anywhere on distributed loads on unevenly sloped surfaces / ...
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### Moving internal forces for the sake of stress

I am studying mechanics of materials and I'm confused with determining internal forces for the sake of stresses. Consider this diagram: (just for visualization. from Beer Johnston book) when ...
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### Superposition of cylinder stress and normal stress

I need to calculate the principal stresses for the given cylinder with thick walls inside filled with gas shown on this picture: I used the Lamé equations, namely: \sigma_{x} = p\cdot\frac{r_{1}^2}{...
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### How can I reduce static friction in a small rotary encoder?

-- Note: I've flagged this as unlikely to be a quality question. I've refined it and rephrased it as a Mathematics SE focused one instead. Find it here. I am using a rotary encoder as a pivot point ...
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### What grade of steel best suits this application?

Take a long, thin, straight wire with a circular cross section. Say, .5mm in diameter and 200mm in length. Hold the wire horizontally at one end (cantilever). What grade of steel would result in the ...
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### Deflection of hanging beam in two parts

Can anyone quickly explain the analytical method for finding the deflection at the base of a beam shaped like this? Note the top beam is a truncated cone and the bottom is a uniform cylinder.
1 vote
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### What material performs best in this situation?

Take a long, thin rod, say .25 mm in diameter and 200 mm in length. Filling these fixed dimensions, what kinds of materials could the rod be made of such that it minimizes how much the rod bends under ...
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### Calculating deflections on an inclined beam

I'm applying a force to a stepped inclined beam (that's what I'm calling it; don't know what the correct technical term would be) in which it's essentially a cantilever with the first section angled ...
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If I have a 2D box with uniform mass of width $w$ and height $h$. I apply a torque $\tau_O$ to the centre of the box, labeled $O$. The box has a fixed point $A$ at the bottom left around which it may ...