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Direct influence of residual stress on the bending stiffness of cantilever beams

Submitted by Bin Liu on

Although the cantilever beam has been widely used as a sensor to measure various physical quantities, important issues such as how residual stress affects its bending stiffness and what are the underlying physical origins have not been fully understood. We perform both theoretical analyses and finite-element simulations to demonstrate for the first time that without changing the material tangent stiffness, residual stress within the beam can directly influence the bending stiffness of the beam. This direct influence arises from two origins: geometry nonlinearity and Poisson’s ratio effect.

Symposium in honor of Prof. Roger Fosdick at PACAM XIII

Submitted by tadmor on
Dear Colleague:

Roger Fosdick will be retiring this year from his position as Professor of Aerospace Engineering and Mechanics at the University of Minnesota. In his honor, we are organizing a symposium on the "Continuum Mechanics of Solids and Fluids" at PACAM XIII (Thirteenth Pan-American Congress of Applied Mechanics). The conference will be held in Houston, Texas during May 22-24, 2013. More information is available here:

Fatigue of polymer-supported Ag thin films

Submitted by Gi-Dong Sim on

The fatigue behavior of Ag films on polyethyleneterephthalate substrates was studied using electrical resistance measurements.
Scanning electron microscopy images showed two types of failure: typical fatigue failure with extrusion–intrusion pairs, and ductile
failure with local necking. Once through-thickness cracks are formed in the metal layer, cracks propagate and the resistance increases abruptly for both failure modes. The effect of adhesion on fatigue life is discussed in terms of concurrent delamination, crack initiation and propagation.

Improving the stretchability of as-deposited Ag coatings on poly-ethylene-terephthalate substrates

Submitted by Gi-Dong Sim on

In this paper, we report that silver films evaporated on poly-ethylene-terephthalate (PET) substrates coated with an acrylic primer can be stretched beyond 70% without fracture. As-deposited films show a larger failure strain than annealed coatings. These observations are rationalized in light of a ductile fracture mechanism where debonding from the substrate coevolves with strain localization. The results of this study indicate that PET substrates coated with an acrylic primer layer may be suitable for stretchable electronics.

Journal Club Theme of December 2012: Metamaterials Inspired Concepts for Elastic Wave Energy Harvesting

Submitted by ruzzene on

Recent journal club posts have illustrated the interesting and unique dynamic properties of phononic crystals and acoustic metamaterials (see April and May journal club entries by M. Hussein and A. Spadoni respectively). The ability of this class of engineered materials and structures to guide and focus elastic and sound waves can be exploited in a number of new applications and exciting functionalities.

Postdoc or Research Associate opening on bi-metallic friction stir welding joining at Texas A&M university at Qatar

Submitted by gayoub on

The work involves working independently and collaboratively on: Identifying processing parameters that will optimize the properties of the bi-metallic joint, developing a material constitutive model for impact loading conditions, developing an experimentally validated numerical model the can be used to predict the joint performance under impact loading conditions, and developing design and processing guidelines for the bimetallic joints.

PhD position in nano-/micro mechanics

Submitted by pooria pasbakhsh on

 One PhD student position is available at Monash University, Sunway Campus in Malaysia with the leadership of Prof A.K Soh. 

 We expect students with the knowledge and experience in at least two or more of the following skills:



1. nano-/micro-mechanics.

2. computational mechanics.

3. fabrication and characterization of advanced materials, e.g.nano-thin-films, nano-wire arrays, functional materials, etc.

4. strong physics/chemistry knowledge, e.g., quantum mechanics.

 

PhD Candidate Positions in Analysis of Composite Materials and Structures

Submitted by jansen on

At Leibniz Universität Hannover, Institute of Structural Analysis, several PhD candidate positions in the field of analysis of composite materials and structures are available (High cycle fatigue of composite materials,  Material modelling for clinching, Structural analysis of wind turbine rotor blades with morphing trailing edge (2 positions), Virtual development of nanoparticle-reinforced composite materials).