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.
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.
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.
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.
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.
Global Engineering and Materials, Inc. (GEM) is looking for candidates to fill positions of Research/Software Development Engineers.
Please refer to the attached file for detailed information. Thanks!
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).
