Hello all

I wondering anyone could help me with the following:-

When plotting a stress strain curve for a material I believe it is normal practice to express Strain in %.

My question would be that when calculating Youngs modulus is it typical to use Strain in units of %?

I if was to plot my stress strain curve then my equations would be:-

Stress = Force / Area

Strain = (Change in Length / Original Length)*100 (Strain is now in units of %)

If I wanted to calculate Youngs Modulus then my equation would be either:-

Youngs Modulus = (Force/Area) / [(Change in Length / Original Length)*100]

Or

Youngs Modulus = (Force/Area) / (Change in Length / Original Length)

Can anyone help?

Thanks

]]>I wondering anyone could help me with the following:-

When plotting a stress strain curve for a material I believe it is normal practice to express Strain in %.

My question would be that when calculating Youngs modulus is it typical to use Strain in units of %?

I if was to plot my stress strain curve then my equations would be:-

Stress = Force / Area

Strain = (Change in Length / Original Length)*100 (Strain is now in units of %)

If I wanted to calculate Youngs Modulus then my equation would be either:-

Youngs Modulus = (Force/Area) / [(Change in Length / Original Length)*100]

Or

Youngs Modulus = (Force/Area) / (Change in Length / Original Length)

Can anyone help?

Thanks

Hi all

I was wondering if anyone could help with determining whether a statement regarding compressive column testing is valid or not.

2 x Columns were loaded compressively (same dimensions), the results revealed:-

Column A has a Eulers Critical Load of 83525N and a Youngs Modulus of 2284N/mm^2

Column B has a Eulers Critical Load of 65493N and a Youngs Modulus of 1791N/mm^2

Would it be correct to say that since column A had a greater Youngs Modulus you would expect column A to also have a greater critical load.

Would this be a valid statement?

Thank you.

]]>I was wondering if anyone could help with determining whether a statement regarding compressive column testing is valid or not.

2 x Columns were loaded compressively (same dimensions), the results revealed:-

Column A has a Eulers Critical Load of 83525N and a Youngs Modulus of 2284N/mm^2

Column B has a Eulers Critical Load of 65493N and a Youngs Modulus of 1791N/mm^2

Would it be correct to say that since column A had a greater Youngs Modulus you would expect column A to also have a greater critical load.

Would this be a valid statement?

Thank you.

Hi all

I was wondering if someone could help shed some light on interpreting a stress strain curve (attached).

It appears that two timber types (soft and hard wood) were loaded parallel and perpendicular to the grain and the stress strain curve produced.

I am trying to make sense of it.

So far i can say that:

loading parallel to the grain for both wood types results in a steeper stress/strain curve thus the young's modulus is greater when loading parallel to the grain, thus the material is stiffer.

I was struggling to make any more sense out of it and i was wondering i could get the opinions of the community?

Thank you.

I was wondering if someone could help shed some light on interpreting a stress strain curve (attached).

It appears that two timber types (soft and hard wood) were loaded parallel and perpendicular to the grain and the stress strain curve produced.

I am trying to make sense of it.

So far i can say that:

loading parallel to the grain for both wood types results in a steeper stress/strain curve thus the young's modulus is greater when loading parallel to the grain, thus the material is stiffer.

I was struggling to make any more sense out of it and i was wondering i could get the opinions of the community?

Thank you.

Hello all

I was wondering if someone could help with the following:-

I am trying to understand the concept of principal stresses in terms of soil mechanics.

I have a soil element that is being loaded by 25kN. I am trying to draw all of the stresses the soil element experiences.

I have attached a drawing of my soil element, the bit I cannot get my head round is the last cube which I got from an online source which shows the Principal stresses 1 3, would it be correct to say that:-

Sigma1 = 25kN worth of stress acting downwards & upwards

Sigma3 = ?????? No idea where this comes from?

Any ideas?

Thank you.

I was wondering if someone could help with the following:-

I am trying to understand the concept of principal stresses in terms of soil mechanics.

I have a soil element that is being loaded by 25kN. I am trying to draw all of the stresses the soil element experiences.

I have attached a drawing of my soil element, the bit I cannot get my head round is the last cube which I got from an online source which shows the Principal stresses 1 3, would it be correct to say that:-

Sigma1 = 25kN worth of stress acting downwards & upwards

Sigma3 = ?????? No idea where this comes from?

Any ideas?

Thank you.

Hello All

I was hoping someone could help me with my understanding of obtaining Stress & Stress From load deflection data.

I have a timber sample which underwent a compression test (dimensions of 30 x 30 x 30).

The test was done 3 times in order to obtain an average.

1) One the first test I had 100 rows of load vs deflection data, on the second test I had 112 rows of load vs deflection data and the 3rd test I had 96 rows. I was wondering if someone could tell me how i would obtain an average of the Load vs Deflection and an Average Stress and Strain???

2) The question relates to Strain which I know is obtained from Change in Length / Original Length - My question is if I had the data below and given the fact that the dimension of my sample was 30 x 30 x 30 then would the following values of strain be correct:-

Load, Deflection, Strain

2, 2100, 2/30 = 0.0667

2.5, 2300, 2.5/ 30 = 0.083

Any help or guidance would be greatly appreciated.

I have attached a screen shot of my data of all three tests.

Thank you.Sample.png

I was hoping someone could help me with my understanding of obtaining Stress & Stress From load deflection data.

I have a timber sample which underwent a compression test (dimensions of 30 x 30 x 30).

The test was done 3 times in order to obtain an average.

1) One the first test I had 100 rows of load vs deflection data, on the second test I had 112 rows of load vs deflection data and the 3rd test I had 96 rows. I was wondering if someone could tell me how i would obtain an average of the Load vs Deflection and an Average Stress and Strain???

2) The question relates to Strain which I know is obtained from Change in Length / Original Length - My question is if I had the data below and given the fact that the dimension of my sample was 30 x 30 x 30 then would the following values of strain be correct:-

Load, Deflection, Strain

2, 2100, 2/30 = 0.0667

2.5, 2300, 2.5/ 30 = 0.083

Any help or guidance would be greatly appreciated.

I have attached a screen shot of my data of all three tests.

Thank you.Sample.png