We are seeking to hire an outstanding candidate as a post-doctoral fellow to work on large-scale molecular dynamics of polymers and polymer composites. The project focuses on the characterization of the molecular mechanisms that govern the mechanical responseof these materials. The successful candidate will work in the Strachan group and will have the opportunity to interact with experimentalists and theoreticians in academia, industry and national labs.

I need help to determine or contruct the crack reistance (R-curve) of a material that show crack bridging. I have the experimental data of applied load and crack lengths due to these applied loads. the SENB specimen was used and loading was 4-pt-bending. The plot of Kapp versus crack size did not give the usual rising curve which plateaus, but rather increases exponentially. How do I get the Kb (i,e K due to bridging) or the normal R-curve. I am not a mechanical engineer but into applied mechanics.

We have read some papers of stroh formalism and the textbook of Tom Ting, and found that the stroh formalism and the hamilton system proposed by prof.zhong wanxie had some relation. We want to know whether the stroh formalism is enough for the analysis of the anisotropic elastic? Thus's to say, for some problems could not  give the satisfied answer which we may try the hamilton framework. I briefly compare the two methods as follows:

This paper revisits continua with microstructure from a geometric point of view. We model a structured continuum as a triplet of Riemannian manifolds: a material manifold, the ambient space manifold of material particles and a director field manifold. Green-Naghdi-Rivlin theorem and its extensions for structured continua are critically reviewed.

Would you give me some hints or recommendate a relative book about this problem?

I am using an MPC subroutine (ABAQUS Standard) that will allow me to release nodes along the line of symmetry which also happens to be my defined crack-path when the strain at that point crosses a critical value. This is to simulate crack propagation using the Critical Plastic Strain Fracture Mechanics Model (CPFSM) / Rice-Tracey model.

I am having trouble in defining the MPC in my *.inp file as I am unaware of as to how to define the nodes upon which I intend to impose the MPC. The manual instructs one to type the individual nodes following the command line: