Automating the welding process for the shipbuilding industry is very challenging and important, as this industry relies heavily on quality welds. Conventional robotic welding systems are seldom used because the welding tasks in shipyards are characterised by non-standardised workpieces which are large but small in batch sizes. Furthermore, geometries and locations of the workpieces are uncertai...

Optimal design of laminated composite stiffened panels of symmetric and balanced layup with different number of T-shape stiffeners is investigated and presented. The stiffened panels are simply supported and subjected to uniform biaxial compressive load. In the optimization for the maximum buckling load without weight penalty, the panel skin and the stiffened laminate stacking sequence, thickne...

Web of plate girders in bridges are usually reinforced by welded transverse stiffeners inorder to improve their shear capacity. Due to problems associated with field welding and fatigue,welded stiffeners are not suitable for retrofitting existing bridges. Bolted stiffeners are a practicalalternative for strengthening girders that are expected to experience shear stresses in excess of theirdesig...

Under severe earthquakes, eccentrically braced frames might experience large inelastic deformations, and the inelastic action is restricted primarily to the ductile links. In order to study the reasonable design method for links, seventy analyses of links are conducted to investigate the effect of different flange width-thickness ratio and length, fifty links are also designed to study the infl...

A new design for a multi-layer dielectric elastomer actuator, reinforced with periodic stiffeners is presented. The resulting actuator enables complex out-ofplane motion without the need of the elastomer membrane prestretch. An in situ optical imaging system is used to capture the complex deformation pattern and track the non-planar displacement and curvature under the applied voltage. The role...

A new design for a multi-layer dielectric elastomer actuator, reinforced with periodic stiffeners is presented. The resulting actuator enables complex out-ofplane motion without the need of the elastomer membrane prestretch. An in situ optical imaging system is used to capture the complex deformation pattern and track the non-planar displacement and curvature under the applied voltage. The role...

A vibration based damage identification algorithm is implemented to assess the damage of a thin–walled composite structure. The structure analysed is a skin with stiffeners, as frequently applied in aircraft components. Both experimental and numerical studies on a single composite skin–stiffener structure showed that the modal strain energy damage index (MSE–DI) algorithm is a suitable method f...

Woven fabric reinforced composite materials are typically applied in plate or shell structures, such as ribs, stiffeners and skins. Products of this type can be manufactured with several processes. A few examples are compression moulding, diaphragm forming, matched metal die forming and Rubber Press Forming (RPF). Shape distortions can occur during manufacturing of composite products. During th...

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...

This study analyses the cost structure of the several processes associated with the shipbuilding industry. The analysed productive processes are: the cutting preparation procedures; the several steel plate cutting processes; the processes of hull plates and stiffeners forming; the associated transport and assembling of plates and profiles; and finally the welding processes. The paper includes 2...