Stiffened plates are employed in various engineering structures including aerospace, civil, naval, etc. These may be subjected to harmonic loads. Therefore, it is essential understand the response of a cracked stiffened structure. This study presents effects crack location on free vibration and plates. For this purpose, horizontal vertical cracks modelled throughout fixed from two-side The anal...

Aryl azides were treated with allenylmagnesium bromide to generate 1,5-disubstituted butynyl 1,2,3-triazoles in a domino fashion, which upon Cu(I) catalyzed 1,3-dipolar cycloaddition with aryl azides afforded novel bis-1,2,3-triazoles in quantitative yields. The final products were analyzed for their antimicrobial activities against a panel of bacterial and fungal strains which revealed the pro...

A knock-down factor is commonly used to take into account the obvious decline of the buckling load in a cylindrical shell caused by the inevitable imperfections. In 1968, NASA guideline SP-8007 gave knock-down factors which rely on a lower-bound curve taken from experimental data. Recent research has indicated that the NASA knock-down factors are inclined to produce very conservative estimation...

We study the thermal buckling behavior of cylindrical shells reinforced with Functionally Graded (FG) wavy Carbon NanoTubes (CNTs), stiffened by stringers and rings, and subjected to a thermal loading. The equilibrium equations of the problem are built according to the Third-order Shear Deformation Theory (TSDT), whereas the stiffeners are modeled as Euler Bernoulli beams. Different types of FG...

Deployable structures are a common spacecraft configuration feature. Deployables are used to configure spacecraft inertia properties, provide expanded antenna aperture and solar array area, or to provide separation between spacecraft components. Lightsat design would be especially enhanced by small size lightweight deployable structures. A review of the state of the art of deployable structures...

Mechanical vibrations induced in flexible structures such as beams and plates have been researched through various optimization functions and control theories to optimize transient response dynamic characteristics. Piezoelectric materials sensors/actuators have been used to reduce and control these vibrations. However, stiffened plate has not been investigated and it is a main and important par...

Patients with sickle cell anemia (SCD) and pulmonary hypertension (PH) have a significantly increased risk of sudden death compared to patients with SCD alone. Sickled red blood cells (RBCs) are stiffer, more dense, more frequently undergo hemolysis, and have a sixfold shorter lifespan compared to normal RBCs. Here, we sought to investigate the impact of increased RBC stiffness, independent of ...

The fundamental natural frequency of the closed cusps of porcine bioprosthetic valves, fabricated from the normal leaflets of pig aortic valves, was estimated using a finite element model. Both normal and stiffened leaflets were considered in the vibrational analysis. The effects of conditions that simulated degeneration, such as stiffening, central perforation, a tear, calcium deposits in the ...

PURPOSE To develop a method for evaluating viscosity and elasticity of the cornea and to examine the effect that both properties have on hysteresis. METHODS A three-component spring and dashpot model was created in Simulink in Matlab to represent the purely elastic and viscoelastic behavior of the cornea during a measurement using device called an ocular response analyzer (ORA). Values for el...

The current study presents a mathematical modeling for sandwich panels with foam filled orthogonally rib-stiffened core using Heaviside distribution functions. The governing equations of the static problem have been derived based on classical lamination theory. The present model contains three displacement variables considering all of the stiffness coefficients. A closed form solution using Gal...