Saab AB

About: Saab AB is a company organization based out in Thun, Switzerland. It is known for research contribution in the topics: Antenna (radio) & Signal. The organization has 862 authors who have published 928 publications receiving 8807 citations. The organization is also known as: Saab AB & Svenska Aeroplan AB.

Electricity generating device for use in an armour arrangement, and an armour arrangement of this kind

Abstract: An electricity generating device for use in an armor arrangement, and to an armor arrangement. The armor arrangement includes two inert reactive armor modules arranged one behind the other, which each include a plate made of inert material, interposed between steel plates. Sheet-shaped members are mounted or baked onto the inert material. The sheet-shaped members are provided with a number of mutually separate regions in which, or next to which, there are disposed elements which convert mechanical vibrations or shock waves in the inert material into electrical voltage. The elements can include crystals or piezoelectric layers. The ammunition part or ammunition effect which penetrates the inert reactive armor modules and which generates the mechanical vibrations or shock waves provokes in one or more elements the generation of a voltage which can be used to initiate counteragents against the penetration.

Missile launching system, and a hanger member for suspending the missile in a launch rail

Abstract: A missile launching system including a launch rail for attachment to an aircraft and having a longitudinal slot, and at least two hangers for attachment to the missile at longitudinally spaced locations thereof and having a cross-section configured to be received in the longitudinal slot in the launch rail. The rearmost hanger includes two separable main parts, including a first main part for engagement with a respective lateral, first groove section of the slot, and a second main part configured to be attached to the missile and be slidably guided in a second groove section of the slot normal to the first groove section and opening towards the missile. The second main part includes laterally extending collars configured to interact in close proximity with respective rail sections facing the missile. The second main part is configured to separate from the first part when launching the missile.

Interlaminar stresses in composite notched and unnotched laminates

Abstract: The purpose of this paper is to determine the interlaminar stress distribution at curved and straight free edges for quasi-isotropic and zero-dominated laminates. The interlaminar stresses are calculated using a three-dimensional finite-element code with error control. For straight free edges the results are compared to existing semi-analytical methods. Another objective with this investigation is to evaluate a quadratic failure criterion for prediction of initial load for delamination and the most likely position for the delamination. In this paper it is found, for quasi-isotropic stacking sequences, that it is not possible to tailor a stacking sequence so that σ z becomes compressive near hole boundaries or at straight free edges. On the contrary both tensile and compressive stresses appear in a periodic manner through the thickness. It can also be concluded that interlaminar stresses exhibit a thickness effect for repeating bundles. The singularity of the interlaminar components is concentrated to a narrow region, approximately 1-2 fibre diameters in thickness and radial direction. Since the interlaminar stresses are so localised, a continuum approach will not provide useful solutions in this area. Consequently the material cannot be treated as homogeneous in this region, instead the heterogeneous nature within each ply should be modelled. The smallest element size in the present analysis for the refined mesh is less than 1 μm, i.e., far less than a fibre diameter. Utilising a quadratic failure criterion, for the studied quasi-isotropic laminates, in conjunction with obtained FE-results, it is shown that global strain to initiate delamination does not depend on the stacking sequence, but so does the number of possible initiation points. For quasi-isotropic layups with a circular cut-out, initiation of delaminations occurs at approximately the same global strain, 0.25%. For unnotched zero-dominated layups initiation and fracture strain are almost the same, i.e., ∼1.2%. The investigation also shows that the number of ±45°/0° or ±45°/90° alterations should be kept at a minimum to minimise the interlaminar stresses and possible damage initiation points. It is likely that the primary cause for delamination initiation for notched plates are the high interlaminar shear stresses and not the normal stresses. Finally it is demonstrated that available semi-analytical methods do not correctly describe the interlaminar stress distribution.