in this research, softening and ratcheting behaviors of ck20 alloy steel cylindrical shells were studied under displacement-control and force-control cyclic axial loading and the behavior of hysteresis curves of specimens was also investigated. experimental tests were performed by a servo-hydraulic instron 8802 machine. the mechanical properties of specimens were determined according to astm e8...

This paper is concerned with a new type of deployable structures that can be rolled up like a tape measure but, unlike a tape measure, are stable in two different configurations. The key to the behaviour of these structures is a particular type of composite construction based on an anti-symmetric lay-up of glass fibres in a polypropylene matrix. The paper presents a finite element analysis usin...

It is well known that it is very difficult to manufacture perfect thin cylindrical shell. Initial geometrical imperfections existing in the shell structure is one of the main determining factor for load bearing capacity of thin cylindrical shell under uniform lateral pressure. As these imperfections are random, the strength of same size cylindrical shell will also random and a statistical metho...

The high efficiency of monocoque cylindrical shells in carrying axial loads is curtailed by their extreme sensitivity to imperfections. For practical applications, this issue has been alleviated by introducing closely stiffened shells which, however, require expensive manufacturing. Here we present an alternative approach that provides a fundamentally different solution. We design symmetry-brea...

Generally, thin cylindrical shells are susceptible for geometrical imperfections like non-circularity, non-cylindricity, dents, swellings etc. All these geometrical imperfections decrease the static buckling strength of thin cylindrical shells. In this work, neighbourhood effect of two circumferential short dents on the buckling behaviour of thin short stainless steel cylindrical shell is studi...

The Layerwise Shell Theory is used to model discretely stiffened laminated composite plates and cylindrical shells for stress, vibration, pre-buckling and post-buckling analyses. The layerwise theory reduces a 3-D problem to a 2-D problem by expanding the 3-D displacement field as a function of a surface-wise 2-D displacement field and a 1-D interpolation polynomial through the shell thickness....

The fundamental frequencies and mode shapes of steel and carbon fiber–reinforced plastic (CFRP) cylindrical shells with steel inserts were investigated using finite element analysis and modal testing. The free-free boundary condition was tested with modal testing using the roving hammer method and verified by finite element analysis using ABAQUS. The results show good agreement between the test...

Due to their light weights and high load carrying capacities, composite structures are widely used in various industrial applications especially in aerospace industry. Stiffening ribs are the main features of lattice type composite structures. Strength to weight ratio is known to be as one of the most critical design parameter in these structures. In this study, the effect of some parameters su...

Vibrations of circular cylindrical shells made of layered composite materials are considered. The shells are weakened by circumferential cracks. The influence of circumferential cracks with constant depth on the vibration of the shell is prescribed with the aid of a matrix of local flexibility coupled with the coefficient of the stress intensity known in the linear elastic fracture mechanics. N...