We describe a surface force apparatus designed to probe the rheology of a nanoconfined medium under large shear amplitudes (up to 500 microm). The instrument can be operated in closed loop, controlling either the applied normal load or the thickness of the medium during shear experiments. Feedback control allows us to greatly extend the range of confinement/shear strain attainable with the surf...

A revised procedure for the design of steel plate shear walls is proposed. In this procedure, the thickness of the infill plate is found using equations that are derived from plastic analysis of the strip model, which is widely accepted for the representation of steel plate shear walls. Equations are derived from a basic steel plate shear wall configuration but are shown to be conservative for ...

In this Letter we discuss theoretically the instabilities of thermotropic freely standing smectic- A films under shear flow [3]. We show that, in Couette geometry, the centrifugal force pushes the liquid crystal toward the outer boundary and induces smectic layer dilation close to the outer boundary. Under strong shear, this effect induces a layer buckling instability. The critical shear rate i...

Zero-net mass-flux jet based control of flow separation over a stalled airfoil is examined using numerical simulations. Two-dimensional simulations are carried out for a NACA 4418 airfoil at a chord Reynolds number of 40,000 and angle of attack of 18 deg. Results for the uncontrolled flow indicate the presence of three distinct natural time scales in the flow corresponding to the shear layer, s...

Physical properties (chemical adsorption rate, viscoelasticity, thickness, and conformation) for self-assembled monolayers (SAMs) of mercapto oligo (ethylene oxide) methyl ethers on gold were determined by quartz crystal microbalance (QCM). The values of thickness, shear viscosity and elastic shear modulus of SAMs increase with unit number of oligo (ethylene oxide) segment. However, the chemica...

We investigate the system size-dependent rheological response of branched type I collagen gels. When subjected to a shear strain, the highly interconnected mesh dynamically reorients, resulting in overall stiffening of the network. When a continuous shear strain is applied to a collagen network, we observe that the local apparent modulus, in the strain-stiffening regime, is strongly dependent o...

A new solution in closed form is obtained for the thermomechanical deformations of an isotropic linear thermoelastic functionally graded elliptic plate rigidly clamped at the edges. The through-thickness variation of the volume fraction of the ceramic phase in a metal–ceramic plate is assumed to be given by a power-law type function. The effective material properties at a point are computed by ...

in this paper, thermo-elastic analysis of a rotating thick truncated conical shell subjected to the temperature gradient, internal pressure and external pressure is presented. given the existence of shear stress in the conical shell due to thickness change along the axial direction, the governing equations are obtained based on first-order shear deformation theory (fsdt). these equations are so...