in this paper, a new analytical method is proposed to study the effect of crack and axial load on vibration behavior and stability of the cracked columns. using the local flexibility model, the crack has been simulated by a torsional spring with connecting two segments of column in crack location. by solving governing eigenvalue equation, the effect of crack parameters and axial load on the nat...

The design rules for centrically compressed stainless steel equal-leg angle members are not explicitly stated in the current European standard SRPS EN 1993-1-4. This paper summarizes results of extensive research conducted on this type structural elements aiming to define recommendations their design. Based a systematic experimental investigation, detailed numerical analysis was performed, and ...

design and construction of efficient and economic reinforced concrete (r.c.) hyperbolic cooling towers have driven the engineers toward the design of tall and thin-shell towers which have considerable high slenderness aspect ratio. consequently, the shell of r.c. cooling towers with relative high slenderness aspect ratio is extremely prone to buckling instability due to wind loading. to increas...

This work considers the problem of modeling visco-elastically coupled rigid bodies, with application to modeling and computer simulation of spatial, flexural mechanisms. Two modeling methods are presented, both of which use elements of screw theory and dual number calculus. The potential utility of the methods is demonstrated by simulating the behavior of a complex spatial, flexural mechanism. ...

This paper investigates the buckling behavior of piezoelectric nanowires under distributed transverse loading, within the framework of the Timoshenko beam theory, and in the presence of surface effects. Analytical relations are given for the critical force of axial buckling of nanowires by accounting for the effects of surface elasticity, residual surface tension, and transverse shear deformati...

We study the magneto-elastic coupling behavior of paramagnetic chains in soft polymer gels exposed to external magnetic fields. To this end, a laser scanning confocal microscope is used to observe the morphology of the paramagnetic chains together with the deformation field of the surrounding gel network. The paramagnetic chains in soft polymer gels show rich morphological shape changes under o...

A laser-based method has been developed for experimentally probing single red blood cell (RBC) buckling and determining RBC membrane rigidity. Our method combines a liquid flow cell, fluorescence microscopy, and an optical-trap to facilitate simple measurements of the shear modulus and buckling properties of single RBCs, under physiological conditions. The efficacy of the method is illustrated ...

The buckling of hexagonal layers in bulk and nanostructures of AlN is analyzed in the framework of atomistic and first principles techniques. At ambient conditions, the wurtzite structure (B4) of AlN consists of buckled hexagons. On the other hand, a non-buckled Bk structure is found to be metastable at zero pressure, being favored at higher pressures. It is suggested that the energy ordering o...

Analytical models that predict modulus degradation in cortical bone subjected to uniaxial fatigue loading in tension and compression are presented. On the basis of experimental observations, damage was modeled as self-limiting for tension but not for compression. These mechanistic uniaxial damage models were then developed into a model for flexural fatigue of cortical bone based on laminated be...

In this research, creation of higher mechanical natural fiber mat composites was proposed. The hybrid mat with jute and glass mat was fabricated by needle punching system, in which jute mat was placed on glass mat. The ratio of jute and glass mat layers was set to be 1:0,1:1,1:2 and 2:1, respectively. The composites were fabricated by hand-lay up method with unsaturated polyester resin after ne...