Questions tagged [stresses]

The tag has no usage guidance.

17 questions
Filter by
Sorted by
Tagged with
6k views

Why is the point of failure load lower than the peak load? [closed]

In a tensile test the peak load was 69kN, but the point of failure load was 60kN. Why is it lower?
14k views

Why do we even use engineering stress?

Surprisingly this hasn't been asked before, so I must be missing something simple. We use engineering stress and engineering strain in this eq. Stress = (Young's modulus) × (strain). This eq. is ...
• 153
12k views

Interpretation of shear flow/shear center of L-profile

I have calculated the shear flows and center of an L shaped profile. I assume they are correctly calculated (I followed the same steps as during the lectures for an I shaped profile). However, I have ...
• 83
5k views

Why do stress concentrations really occur?

From doing some research I've learned that internal stresses inside an object can "concentrate" on sharp edges, as shown in the above picture. For that reason we often make fillets so that the change ...
• 2,259
12k views

Why is the Stress vs strain diagram preferable to the Load vs displacement diagram?

I’m really unsure what is the difference between stress vs. strain and load vs displacement graphs and why stress-strain is better. I know that the units are different: stress is in MPa and the load ...
341 views

How exactly do forces transfer in different directions?

If we imagine the load being placed at the top of the below triangle, I realise that the downwards force is transferred into one which goes in a 'south east' and 'south west' direction down to the end ...
702 views

Principal Planes and Principal Stresses

Consider that a state of plane stress exists at a point and the stresses acting on an element taken at that point are given as, The normal stress acting at any plane of this element inclined at an ...
8k views

Why exactly does a washer help distribute the stress around a bolt?

Usually the reason for having a washer under a bolt head is stated to be that it helps to evenly distribute the stress to the clamped material surface. But why is this? I would understand if the ...
• 2,259
3k views

Calculating maximum internal pressure from maximum rated external pressure?

Is there a calculation / rule of thumb that can determine a containers rough maximum negative pressure (vacuum) from it's rated internal pressure (assuming a single layer construction so there is no ...
• 275
10k views

Properties of an hexagonal shape vs round tube shape

In a bike frame build, are there any differences between hexagonal cross-section tube instead of the typical round tubes? Assuming that both are made from the same aluminium alloy and have the same ...
• 133
650 views

What's the difference between critical load and yield stress, and failure in general?

So far, I have learned of three quantities that are related to the failure of a beam (axial and longitudinal loads). The first illustrates the stress under which balsa wood will undergo plastic ...
14k views

What is the difference between tau = VQ/It and tau = V/A?

What is the difference between the formulas $\tau = VQ/It$ and $\tau = V/A$ for finding shear stress due to transverse loading? I understand that the use of first moment of area, is the only reason ...
193 views

How to calculate residual strength of a corroded structure from their stress values?

Currently, I have an actual entire corroded bridge model in the FEM analysis in Abaqus I want to estimate the residual strength of this bridge due to corrosion from the output results in the Abaqus, I ...
1 vote
413 views

Shear Stress Formula

Could anyone tell me what the variables in this formula are? $$\tau=\frac{S\;a\; \bar{v}}{I\; t}$$ I believe it is used for shear stress and that $I$ is moment of inertia but unsure on the other ...
• 25
33 views

How to measure strength of stretch film on a mock up

Let's say I have an iron cube of 1 cubic meter and I want to make an aquarium out of it. To hold water I want to wind stretch plastic film around the walls of that experimental aquarium. Let's assume ...