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Mechanism to increase energy efficiency

Submitted by Jigar Y. Patel on

As shown in figure two pulleys can rotate about their axis. Stationary
plate is simply supported on these two pulleys. Now the weight of
stationary plate applied on each pulley in vertical downward direction
is Mg/2. This Mg/2 will divided in two parts. One is tangential and
second is towards the center. Tangential part will help to rotate
pulleys and toward the center part will generate the friction.

Force is stationary and it can help to rotate pulleys at some angle.



Uses and Advantages:

Size effects under homogeneous deformation of single crystals: A discrete dislocation analysis

Submitted by PJ Guruprasad on

 doi:10.1016/j.jmps.2007.03.009

Mechanism-based discrete dislocation
plasticity is used to investigate the effect of size on micron scale
crystal plasticity under conditions of macroscopically homogeneous
deformation. Long-range interactions among dislocations are naturally
incorporated through elasticity. Constitutive rules are used which
account for key short-range dislocation interactions. These include

Extended Chaboche viscoplastic model for cyclic loading

Submitted by Fatigueless on
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These days I've been applying oneself to implement the Chaboche viscoplastic model in ABAQUS user-subroutine for simulating the cyclic loading in single crystals.

The procedure can easily get out. I'm not sure about the problem, the deduction of Jacobian, the convergence? 

Btw, I know there is free subroutine for crystal plasticity by Huang YG. I wonder if the UMAT routine for chaboche model is available, then I can generalize it to fit for my case.

Journal Club Theme of March 15: Impact of Chip-Package Interaction on Reliability of Copper/Low k Interconnects and Beyond

Submitted by Rui Huang on
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The exponential growth in integrated device density has yielded high-performance microprocessors containing almost 1 billion transistors per chip for the current 65 nm technology. Continuous scaling of the devices and performance requires innovations in materials, processes, and designs for both back-end-of-line (BEoL) interconnects and packaging structures. Mechanical reliability has been a limiting factor for implementation of new materials and processes.

Mechanics of growth and rupture of abdominal aortic aneurysm

Submitted by Konstantin Volokh on

We present a coupled mathematical model of growth and failure of the abdominal aortic aneurysm (AAA). The failure portion of the model is based on the constitutive theory of softening hyperelasticity where the classical hyperelastic law is enhanced with a new constant indicating the maximum energy that an infinitesimal material volume can accumulate without failure. The new constant controls material failure and it can be interpreted as the average energy of molecular bonds from the microstructural standpoint.

Post-buckling and Snap-through Behavior of Inclined Slender Beams

Submitted by J Zhao on

In MEMS fields, a need arises in engineering practice to predict accurately the nonlinear response of slender post-buckling beams, especially the nonlinear transverse stiffness. The bistability of the post-buckling beams is excellent in reducing power consumption of micro-devices or micro-systems. However, the major difficulty in analyzing the post-buckling and snap-through response is the intractability of the geometric nonlinear control equations of large deflection beams.