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This paper describes the results of the numerical studies of the cold formed profiles joint assembled in a back-to-back pair compared with experimental tests results. The results are presented for eaves connection and apex connection. The entire study has been performed using KB600-5 and KB450-3,5 thin-walled steel profiles joints. The system is primarily of tow galvanized cold-formed steel profiles so called KB, which are joined by means of steel plates, placed in-between them. Connecting of this assembly is realized by using M20 bolts, witch work with to contact planes in shear. A comparative analysis of the experimental and numerical results was made.

Any building must ensure safety conditions during the exploitation, at the level of designed exigencies, throughout the entire lifespan. The completion degree of the structural performance requirements, in the given exploitation conditions, results following the assessment of the technical state of the building. This paper presents a case study performed on an industrial “ground floor” type building, with the purpose to assess the exploitation safety level for the constituent structural elements and engineered consolidation measures. The structural reliability solutions have been designed in compliance with the execution possibilities limited by the existing of ventilation tubing , of big dimensions , made in France, of ,,polyester reinforced with glass fiber’’, which is situated along columns of axis A, at 30 cm approximate and the owner cannot to interrupt the technological process during the works.

The paper presents a study of fire behaviour of butt-welded connections taken into account the post fire conditions and the possibility of welding strengthening of fire exposed structures. The need of in service life of a steel structure after being exposed to fire raises the problem of strengthening or replacement of some structural elements. The degradation of steel properties with increasing temperature is considered according to Eurocode 3: Part 1-2 provisions. Following the experimental part, the behavior of the welded connections after fire exposure was compared with the original behaviour at the ambient temperature. The results and conclusions can be used for damage assessment and strengthening technique of post fire steel structure.

This research concerning the topic, pursues the design, manufacturing, analysis and testing of the manhole cover that may be used in pedestrian networks. Although there are certain commercially available manhole covers made of glass-reinforced composites, there are a few papers published related to the modelling, simulation and mechanical testing of such parts. Herein, the manhole cover is made of the sandwich composite. The novelty of this kind of cover is to use an oriented strand board (OSB) as the core between two sides containing layers, which are reinforced with glass fibers. The OSB core leads to the increase of the stiffness-weight ratio. The paper describes the materials corresponding to the layers of the composite cover, geometry of the cover, technology used to manufacture the bending specimens and cover tested. Specimens made of materials that correspond to each layer of the cover, are tested in bending in order to determine their mechanical properties (flexural strength and flexural modulus). Bending tests and testing of the cover are also described. The composite manhole cover is also analysed by the finite element method to obtain the state of stresses and strains. The strains of the manhole cover are experimentally measured by using the tensometric method. Finally, comparing the strains with the strains experimentally measured validates the numerical simulation model.

The paper is proposing an advance research on welded joints of the shell steel elements. The assessment of the fatigue of the existing structures is a current topic in the sustainable development of the civil engineering work. Planning, manufacturing and serviceability of the steel structures under cyclic loads, involves a fatigue designing. Simplified fatigue and fracture mechanics based assessment methods are widely used by the industry to determine the structural integrity significance of evaluate cracks, manufacturing flaws, service-induced cracking or suspected degradation of engineering components under normal and abnormal service loads. In many cases, welded joints are the areas to contain the fabrication defects or cracks initiating and growing during service operation. The welded joints are a major component that is often the cause for structure failure or for being the point at which fatigue or fracture problems initiate and propagate. Various mathematical models for various classes of welded joints are developed by analytically or by simulation software's that can be used in fatigue and fracture assessments.