# Questions tagged [deformation]

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### Why is tensorial shear strain half of engineering shear strain?

Small deformation shear strain $\gamma$ in engineering can be expressed as $$\gamma_{xy}=\alpha +\beta ={\frac {\partial u_{y}}{\partial x}}+{\frac {\partial u_{x}}{\partial y}}$$ where $u$ ...
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### Material selection for weight scale

I am looking to test the FlexiForce sensor in measure force, however for accurate readings the load needs to be disturbed evenly over the sensing area. As such I am having "discs" made to cover the ...
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### Yield properties of plastic material

What is meant by yield of isotropic plastic material? How is yield of Isotropic plastic material different from the term normal yield which is referred as transition from elastic behaviour to plastic....
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### How to calculate the adhesion I need to keep a 3D printed bending part straight?

3D printed parts cool down during printing, resulting in thermal contraction which causes a bending moment and separation from the printing bed. The issue is solved by increasing adhesion to the ...
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### Calculating the bending moment ($M$) of a beam as it relates to stress ($σ$) and strain ($ε$)?

I am trying to learn how to work out the bending moment for progressively complex systems to model a beam. I am assuming only one axis of motion (transverse = $y$). For the basic equation of material ...
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### Creep of the materials

Does creep exists for all materials at any stress at room temperature? I searched for this and could not find any answer other than creep isn't significant at low stresses and low temperatures. What I ...
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### Axial deformation of variable cross-section member

I've been given a problem which I've attempted to solve, and hope some fellow engineers could possibly see if my approach is correct. We are asked to calculate a column's axial deformation due to an ...
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### Are Green strain calculations apt for volumetric strains?

I am trying to calculate large volumetric strains but I am somewhat confused whether Green strain is the right thing to be using or whether I should use good old-fashioned engineering strain. The ...
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### Difference between 'plastic yielding' , 'plastic yield strength', plastic strength' and 'plastic stress'?

I am going through a literature where these terms are regularly used and I am confused are they different and if yes then what does each term mean? I also want to know relation of plastic strength of ...
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### Deflection of constrained rectangular plate

Does a standard formula exist for calculating the (maximal) deflection of a constrained rectangular plate that is loaded with a evenly distributed pressure? I found this Useful tables of mechanics, ...
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### Wheel rolling resistance

I think that some of you know what is rolling resistance. It is force that works in opposite direction to roll and is caused due to deformation of tire. It also affects car wheels. There is one ...
2k views

### Springback after a plastic deformation

Before the yield point, the deformation is elastic, and then it is plastic. But what happens to the elastic 'part' of strain after the load is removed? Is it retracted fully or partly, and how does ...
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### Deflection of a stack of disks under applied force/pressure

I'm trying to calculate the deflection of a stack of metallic disks, when subjected to a force. In the case of the figure below, representing a valve for a shock absorber, the force is due to a ...
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### Computing strain in beams

I am studying this problem: The rigid bar ABC shown in Fig. P-212 is hinged at A and supported by a steel rod at B. Determine the largest load P that can be applied at C if the stress in the ...
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### Solid mechanics: Deflection of a rectangular elastic membrane

I am trying to solve for the deflection $w$ of a rectangular membrane with tension $T$ acting on two opposite edges. These two edges are fixed i.e. $w = 0$. The other two opposite edges are free. The ...
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### Behavior of materials on application of tension

Does a test body subjected to a strain that causes plastic deformation still have elastic recovery?
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### Finding initial length of a bended plastic sheet (Bend Allowance)

I have a 1.5 mm thick plastic sheet part which hast to be bent at a joint 0.3 mm thick by ~ 10 Deg. I know (found from design drawing) compressed and stretched lengths of the joint. How can I find the ...
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### Deformation gradient, strain tensor from cylindrical coordinates

I do not have any engineering background but I am studying some mathematics to try and understand and solve this problem. I have a mesh (M1) in cylindrical coordinates and this deforms into a mesh (M2)...
280 views

### Is the calculated shear strain in a beam, engineering strain or tensorial strain?

Recently I came across a FEM code of a linear deformation beam element, and it made me wonder what is the correct relation between shear stress and shear strain in a beam element. In the beam element ...
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### What degree of open span/narrow support can rigid PIR thermal insulating foam sustain under the short term load of setting concrete?

I've found data related to the deformation and shear performance of typical PIR (polyisocyanurate) foams such as Celotex/Kingspan, but I'm not sure how to use these figures in my own situation. I am ...
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### Impact force with unknown deformations or time duration?

I expected to find more documentation on analytical solutions to determine the contact force between bodies, where deformations ($\delta = \delta_{1} + \delta_{2}$) and impact time ($t = t_{f} - t_{i}$...
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Due to the fact that pipe flanges rely on bolts, and bolts rely on friction, it seems obvious to me that in deflecting to meet the load, the nut will immeasurably turn. So my question is - how much? ...
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1 vote
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### Rotation Matrix for a Stress Tensor Matrix

In my engineering mechanics course, I came across the following rotation matrix, for a stress tensor, for a counter-clockwise rotation. However, this is completely different, actually a transpose of ...
170 views

### Should the stiffness of this cantilever beam be different for these two conditions?

So, I was just doing some Finite Element Analysis (FEA) to figure out what would be the effect on the stiffness of a cantilever beam if another beam is attached to it on its free end. Below shows the ...
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### Can stress tensor be defined on feature edges?

Assume a rod is being extruded out of a cylinder by pushing the cylinder into a hole (See Figure below). Do the feature edges (or corners in 2D) cause the traction (the surface force) to be ...
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### Applying forces from the inside of a bar

I was reading Schaum's Outline: Strength of Materials (fifth edition) when I came across this solved example problem from the Tension and Compression chapter: The solution was clear to me, however ...
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### deformable object squeezing

I have the problem following. There is a deformable sphere with radius r. It goes inside a constriction channel with d*d cross section. Assuming that the sphere volume is constant and the sphere shape ...
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### Is there an standard description for deformation at each point on a body?

I'm trying to come up with a way to describe deformation on a body at each point on that body. My problem can be expressed and solved in two dimensions. Given two triangles, one being the initial ...
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### Confusion in deriving von Karman equation for strip rolling

In the derivation for von Karman equation for metal strip rolling, an infinitesimal element is chosen as shown in the picture above. The equilibrium equation for the element is as follows: Upon ...
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### Does the magnitude or range of interaction of a force affect which layer dominates the mechanical response of a multilayered structure?

Suppose I have a two-layered material, with a stiff and thin outer layer (high E) and a soft (low E) and thick inner layer. Intuitively, it feels like the effect of short-ranged forces (e.g., van der ...
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### How to go from a metal sheet to a metal box using (set of) dies only?

As a hobbyist, how to go from a metal sheet to a metal box (1 hollow side) by using (set of) dies only? All videos I watched involved : bending 1 side at 90° then A) cut twice and discard a square ...
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### Fracturing and Necking

I am trying to model the deformation of an object after it has surpassed its UTS, before its ultimate failure, what formulas/methods are used to calculate this? My assumption is they have to do with ...
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### Deformation in nano timescales for stress > UTS

I am investigating the deformation of high-strength carbon steel past its UTS, subject to extreme pressures of order 1e+19 Pa, but applied in small timescales (100-500 ns). For a material, such as ...
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