Recent content by fruitkiwi

Dear HallsofIvy, Thanks for your reply. as i read through the book, i do not know how to start to derive, therefore i start with ellipse form equation. based on your experience, if i am going to derive that equation "principle radii of curvature" of the ellipse, what is the first...

or it is just r1=2b+a?

Hi, dear all, hope your guys allow me to ask this tricky question. Refer to the attachment, i would like to derive the principal radii of an ellipse, the final equation and figure is provided in Stephen Timoshenko Theory of plates and shells 2nd edition. consider the ellipse has form...

Hi, Afreiden, Thanks for physics of classical mechanics. now progressing in this thought "what direction do the principal stretches act if you perform that tension test while simultaneously performing a rigid body rotation on the specimen?" Hi, Studiot, Thanks for the application of...

Thanks for points out my mistake. I edited the post. My mistake, use the wrong image. Ya, my intention is to understand the stretch, not stress. You answered my question.

Dear Studiot, Thank for agree with me on the stretch term i used. I think the strech is 1+εE. Finally I can start to read the books. "In continuum mechanics the analysis is pointwise - that is strains refer to the limiting displacement and deformation shrunk to a point. Note strain...

Dear Studiot, Thanks for your detail evaluations. I think I can differentiate stress and strain, they have clear distinction, :) The one I make mistake is strain and stretch. Currently read about Holzapfel "A continuum Approach for engineering" , that's why i use the term stretch...

Hi, Berkeman, I think it is related to continuum mechanics so i choose to post it here. I have not problem on engineering application, however, in terms of physics definition, erm, I have problem. Hi, Studiot, Thanks for save my post :) The system you refer to is Lagrangian or...

Dear all, I have problem on defining first principal stretch, second principal stretch and third principal stretch. Does it means in x-axis we definite it as first, y-axis is second, third is z axis? what if my load is applied on a cubic from the -y direction in a uniaxial testing...

Hi, jfy4, I actually try to read more, but cannot find resources. 1. so all the N1, N2, N3,should always equal to 1? or under any condition they will change? 2. or can I call them as right stretch tensor?sorry, as i cannot differentiate left and right stretch tensor, so cannot evaluate more...

Hi, Dear all, Facing problem to understand strain energy function invariant terms A typical strain energy function consist of strain invariant can be defined as followed W(I1,I4)=C0+C1(I1-3)(I4-1)+C2(I1-3)^2+C3(I1-4)^2+C4(I1-3)+C5(I4-1), I1 and I4 are so called invariants of Green's strain...

Hi, AlephZero, Thanks for your experience sharing. I fully agree with what you say. Continuum seems no that boring for me now after communicating with you all. start to see star shining in the dark. :) Again, thanks for you and afreiden input.

Hi, afreiden, Yup, you answer all my curiosity. I agree with what you share here. I once be arrogant when i stand in front of solid mechanics. but after seeing your explanation, i realize i am the so small compared to all of you. I will dig into solid mechanics deeply. thanks for your...

Thanks for both of you try to keep thing simple and interesting to me.and not asking me stop think too much. I assume both of you have experienced in solid continuum mechanics , may i know why we use finite strain theory to describe large strain while infinitesimal to describe small strain? My...

Thanks for AlephZero and afreiden input, it give me a deep thought on the physical meaning. because i only know how to calculate,but at the end it give me a question what i am working for. i always thought the basic term of stress is Cauchy stress.and according to my understanding, the 2nd...