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...

Capillary GC Columns and Guard Columns/ Retention Gaps 2 How to Choose a Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Columns by Phase Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Ionic Liquid Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 MS-Grade Columns . . . . . ...

Automatic hydraulic press is widely used for pressing ceramic wall and floor tiles, the four columns of its frame withstand the all work force when it works, so the columns are the key compartments of the frame, and its work performance has an important impact on the structural performance of the entire automatic hydraulic press. Took the column thread connection of 32.8MN automatic hydraulic p...

fiber reinforced polymers (frp) have widely used for the purposes of enhances strength and ductility of concrete columns. proper design of such hybrid columns, however, requires a better recognition of the behavior of concrete columns confined with frp. in this paper, the influence of frp thickness, concrete compressive strength, and column size on the performance of eccentrically loaded reacti...

Concrete filled cold-formed steel-concrete composite columns exhibit improved strength and ductility characteristics due to its ability resist inward buckling as well delay the outward buckling. Though concrete infill prevents buckling, still limits steel section from reaching yield strength. From past studies, it is observed that introducing of web stiffeners in cross-section may improve resis...

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 ...