This study aimed to investigate the effects of stiffeners on buckling of thin cylindrical shells under uniform axial compression. To this end, more than 300 finite element models of stiffened cylindrical shells were prepared. The variables considered are shell thickness, number, dimension and the location of the vertical and horizontal stiffeners as well as circular symmetrical imperfections. R...

We consider a two-fluid compressible flow. Each fluid obeys a stiffened gas pressure law. The continuous model is well defined without considering mixture regions. However, for numerical applications it is often necessary to consider artificial mixtures, because the two-fluid interface is diffused by the numerical scheme. We show that classic pressure law interpolations lead to a non-convex hyp...

To control underwater acoustic radiation of ships and protect against detection, coatings are attached to the vibrating wet surface of the hulls. Coatings with different pores or scatterers enclosed will attenuate vibration and suppress sound radiation with different mechanisms. However, there are very few experimental studies concerning vibration measurement of a coated structure in water, mai...

The design process is becoming increasingly complex with designers balancing societal, environmental and political issues. Composite materials are attractive to designers due to excellent strength to weight ratio, low corrosion and ability to be tailored to the application. One problem with composite materials can be the low stiffness that they exhibit and as such for many applications they are...

Insect wings do not contain intrinsic musculature to change shape, but rather bend and twist passively during flight. Some insect wings feature flexible joints along their veins that contain patches of resilin, a rubber-like protein. Bumblebee wings exhibit a central resilin joint (1m-cu) that has previously been shown to improve vertical force production during hovering flight. In this study, ...

The recently developed Spring Back Reflector has low stiffness in the deployed configuration. A general method of stiffening this type of reflector without changing its folding properties is presented. The stiffening is achieved by adding a conical skirt around the edge of the dish; this skirt snaps elastically when the dish is folded. The paper concludes that it is possible to design spring ba...

Background: Worldwide Intra-Uterine Growth Restriction carries out high rate of fetal and neonatal morbidity and mortality. Perinatal mortality rates are 4-8 times higher for growth-retarded infants. IUGR are subdivided into symmetrical and asymmetrical subtypes. Aim of Study: To focus on the actual incidence of each subtype of IUGR and disparities. Methods: Across-sectional descriptive study a...

The in-plane compressive behaviour of thin-skin stiffened composite panels with a stress concentrator in the form of an open hole or low velocity impact damage is examined analytically. A fracture mechanics model, developed initially to predict notched compressive strength, was applied to estimate the compression-after-impact strength of a stiffened panel; in the analysis the impact damage is r...

The three approaches to too-many-solutions problems discussed in the previous chapter do not treat them as symptomatic of significant generalizations about input-output mappings rather than outputs. Because this systematic challenge to OT is not recognized, previous attacks on these problems, apart from de Lacy's general proposal, see them as an assortment of individual difficult cases and anal...