Stress Strain Fitting...(former Arrays)

[Dumitru]

Hi again. Hope you're all doing great!

I'm back with more on my initial post. Taking into consideration our discussions and after completing the remaining tests, I've reached the attached...

The problems I'm facing next are:

1. I have 30 sets (each of 50 pairs, strains and corresponding stresses) to which I want to find a "mean" - construct a curve which gives, for lets say a given strain, the mean of the stresses (problem is the strains are particular to each and every set)

2. find the tangent in the origin (since most curves have a stabilization step - a preload until a stress of 20 MPa, that means finding the tangent for the curve in this point)

Kind regards, Dumitru

First, I tried to reduce the replies to the first form of my topic (I've saved it all as document so it should be available to everyone) but gave up soon after.

Second, I've renamed it..thanks giraud for suggestion (I kept it in the initial form considering the fact that it would be easier for you collabs out there, who helped a lot, to reference back)

Kind regards, D.

[Dumitru]

Modelul propus reprezintă o extindere a modelului lui Carreira și Chu, (1985, pct. 7), atât pentru BO cât și pentru BIR, cu posibilitatea de a fi adaptată conform rezultatelor experimentale obținut

The above is copy-paste from word...seems to work (still today is my first for this interface, which looks better).

It took me by surprise (panic) to see that the former collab changed its status to read only...until I read about the porting to this newly designed forum.

I understand your problems but I hope they are only temporary...

Now, since my data analysis skills are lower than a greener's...could you help, please?

Kind regards, D.

[jeanGiraud]

"Hello Dumitru"

Most if not all former collabs will be there again.

There is one thing about your project that does not help. You have titled "Arrays"

Yes , you have an array of data, but they are just data ! You should rethread under

a more technical definition for any futur users to be either attracted and maybe

reply from their tool box. An "Array" is an array, so what ?

The nature of your project is really a "Stress Strain" project, a project that consists

in fitting the 30 experiments . Your original project lasted quite a while in the former

Mathcad collab, this is a new community with lot more visitors, ideas and skills.

Your project is simply an applied fitting session to the specific "Stress Strain".

Why not rename it "Stress Strain Fitting" not using the word "diagram" as it is

redundant ... and tag it as such. Then the next visitor, on a blue moon day,

can get at it ... as it stands or as left completed or not completed.

This new web community is attractive, slower ... etc.

Like the "gogo girl" story ... their parents were desperate she had few dates only.

So, they toke the 4 ft tall girl for surgery to elongate her legs, but they forgot to

get her a new skirt, and now "gogo" is like us : learning how to walk .

jmG

Actually the font and size is frozen ... "gogo" is in the dressing room !

"Hello Dumitru"

Most if not all former collabs will be there again.

There is one thing about your project that does not help. You have titled "Arrays"

Yes , you have an array of data, but they are just data ! You should rethread under

a more technical definition for any futur users to be either attracted and maybe

reply from their tool box. An "Array" is an array, so what ?

The nature of your project is really a "Stress Strain" project, a project that consists

in fitting the 30 experiments . Your original project lasted quite a while in the former

Mathcad collab, this is a new community with lot more visitors, ideas and skills.

Your project is simply an applied fitting session to the specific "Stress Strain".

Why not rename it "Stress Strain Fitting" not using the word "diagram" as it is

redundant ... and tag it as such. Then the next visitor, on a blue moon day,

can get at it ... as it stands or as left completed or not completed.

This new web community is attractive, slower ... etc.

Like the "gogo girl" story ... their parents were desperate she had few dates only.

So, they toke the 4 ft tall girl for surgery to elongate her legs, but they forgot to

get her a new skirt, and now "gogo" is like us : learning how to walk .

jmG

Actually the font and size is frozen ... "gogo" is in the dressing room !

[jeanGiraud]

The first problem is that this web is still under construction.

Now I have the font family working [it didn't in the morning]

Actually the work sheets are read only .

Zipped Mathcad work sheets may reduce the size of the

community "data base", so to speak ... but it is not practical

for collaboration . You seem to have reposted the very original

work sheet that kept us busy for 112 times. And fitting the

entire world with 3 coefficients [from recollection] is not

possible.

I'm willing to revisit your project, but on a new work sheet

that will have just the data sets ... NO scripted components

no graphs no nothing, just a data table.

All the work that collabs did [Alvaro, Theodore, jmG ...]

where can we retrieve ? I have passed pieces of fitting

as in-line images in the former Mathcad collab, I can't retrieve

all those hours of work.

From recollection, what you never did was to categorize the

project by experiments. From columns of data to columns

of data, all sorts of creasy graphs appeared. I don't have Winzip

because there are years I don't need. As it looks from dwonloading

your file and clicking on it it open a new session of Mathcad even

there a session in course and it says "read only".

What to do ? .

jmG

The spell check is very poor and worst than Akiva.

Now the spell check is complete on its own,

but the font family is OFF ... what a mess !

[Dumitru]

>> All the work that collabs did [Alvaro, Theodore, jmG ...] where can we retrieve? <<

It's true, that fitting is not in the attached sheet. If you recall, the fitting (initially) was for determining values for a set of coefficients for Wang's model...before fitting (again) I need to group and find a "mean" curve for my stress-strain sets (then apply fitting to the "mean" and see what it gets)...hope the attached is what you need giraud

[jeanGiraud]

... another piece of joke !

When I opened the work sheet it said "Read only"

obviously no possible action on the work sheet except scroll up/down.

I went away for about 1 hr, now the work sheet is active . How come

that happens ? who is deciding what in my box ?

Whatever, your project starts here. Where is the column for stress ?

If each column of strain is paired with a column of stress, then you

must have 30 data sets of two columns each or a single data set of

60 columns collecting the pairs alternately so it can be managed

to scan the data set two columns at time.

Make sure you categorize the data set, what I mean is this:

If the first 10 pairs are normal experiments , put them side by side.

If the next 10 experiments are "abnormal" experiments, keep piling

to the right of the data set, and so on... no mix.

So, your next work sheet will have a data set only of paired columns,

each pair meaning stress,vs strain to plot.

"An error occurred trying to retrieve data from server.

Please try again in a few minutes.

Error Code: 'selection' is null or not an object"

Just someting like this, no plot

jmG

Can't upload the image at the moment !

[Dumitru]

the first column in each set ("data") is the loading (later converted to stress) and the second is the strains - for one sample

the grouping is, at this point, based on the order in which testing has been completed - still working on finding/separating/choosing abnormals from the rest

what your says is (your image) I should group all the strains in one big data set and the same with the stresses?

[jeanGiraud]

Well done the 30 data sets.

This Mathcad web community is actually not viable.

Anything is in error at any moment: the font , the image and now the upload file.

It just scrapped my previous message with important notes.

What's the point saying "In error, try later ..." it scrapped it all, not even capable

to return to the message page .

This work sheet enables exploring the 30 experiments, quick.

They look much more realistic than before.

jmG