Hi everybody,

I have a question about the shear modulus of polymers. As we know, the general engineering polymers （rubbers） are highly extensible and elastic. The shear modulus，G， for the polymers subjected to the small-strain conditions, can be defined by G=NkT, where N is the number of network chains, k is Boltzmann's constant and T is temperature in Kelvins.

Hello everyone,

As reported in some references, Maxwell stress of a dielectric  elastomer subjected to electric field can be determined by the following formula

P=e*E^2    (1) -------e=e0*e1, e0 is the dielectric permittivity of vacuum, e1 is the relative dielectric permittivity of the elastomer, and E is the applied electric field.

However I found another expression from  “Electrodynamics of Continuous Media”. (Landau and E.M. Lifshitz.,Course of Theoretical Physics. Vol. 8. 2nd Edition. Butterworth-Heinemann. Oxford. 1984. L.D. ), which is  described as follow,

(sigma)ik=(e/4/pi)(EiEk-1/2E^2 deltaik)     -(2)   pi=3.14

Dear all,

 I have a puzzling question. 

As we know, the positions of a increment in a FEM analysis ( in abaqus) include :

Dear xuanhe and all,

I have reviewed the paper "Method to analyze programmable deformation of dielectric elastomer layers". (Xuanhe zhao, Zhigang Suo)

It is very insteresting.

I have one question you would like to ask you.  Hope to get your reply.

Recently, I studied  Prof.Suo's lecture "Advanced Elasticity", http://imechanica.org/node/725.

The following is explaination about osmosis pressure in the lecture.

I have one question  about work done by a pressure applied to a system.  The book of Thermodynamics often always present pdV (where dV is the change in the volume of the system. )but never Vdp, Why is that? Is it because we don't treat p as a variable? In a grand canonical ensemble is pressure constant for any system?

Acording to Thermodynamics first law,  du=dq-dw , where dw denotes work done by pressure and external force.  dw=pdv+dw' .   dq=Tds (Thermodynamics second law)

so, dU=TdS-Pdv-dw' 

finally, dG=vdp-sdT-dw'

if we can treat p as a variable, then vdp denotes what?

The cells of our bodies represent a very large class of systems whose structural components often are both comlex and soft. Most cells have a complex internal structure of biological rods,ropes and sheets.

cell mechanics is vital to tissue formation!

I need some introductory materials to be familiar with cell mechanics and soft tissues in biomechanics. I will appreciate your help and guidance!

Best

Marc 

continuity e.q.,equilibrium e.q. ,N-S , constitutive e.q. for elastic solid and compressible fluid in the space-frequency domain, as shown in the following Fig.

i don't understand how can this author deduce? why v=iwu? is this assumption?  why is this necessary?    thanks for your help and guidance!