Analysis of the causes of defects due to quality roofing membranes mechanical anchoring
Anchoring of the layers of flat warm roofs using anchoring elements is nowadays one of the most used technology. This is a frequent technology to repair damaged roofs (total reconstruction, increasing the load on the wind loads, partial repairs etc.). In the European building market there are several suppliers of the enchoring equipment who declare their product’s properties in the european technical approvements (ETA). The goal of the article is to demonstrate results of the carried out measurements and their possible impact into practical application of the mechanically anchored systems. This allows reduce the amount of defects to improving flexible watertight membranes. The topic can be considered actual and due to the large number of defects precisely for these types of roofs.
Eurocode 3: Design of steel structures
Structural engineers should be encouraged that at least in steel, design conforming to Eurocode 3 (BS EN 1993-1-1) is not signifi cantly different to BS 5950. In fact, if the changes in presentation are stripped away, in most areas design is almost identical to both standards. This is of course to be expected, as the steel itself knows no difference, and the UK has enjoyed the benefi ts of mature design standards for decades – it would be very surprising if there were dramatic changes from previous UK practice. There are wellknown changes:
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.