Search results for "Structural Engineering"
showing 10 items of 1998 documents
Interaction between Longitudinal Shear and Transverse Bending in Prestressed Concrete Box Girders
2017
In box girder bridges, the quantity and distribution of reinforcement to be put in concrete elements of sections can be evaluated only by considering the deformation of the cross section in addition to the longitudinal analysis of the static scheme, establishing the entire state of stress of box sections. This leads to a need to evaluate the interaction between internal forces obtained by the global analysis and the ones obtained by the local analysis of the cross sections. The frame effect implies the elastic deformation of slabs and webs, whereas eccentrically applied loads lead to cross-section distortion with the loss of the box shape. Hence, the reinforcement is strongly influenced by …
Influence Of Lateral Load Distributions On Pushover Analysis Effectiveness
2008
The effectiveness of two simple load distributions for pushover analysis recently proposed by the authors is investigated through a comparative study, involving static and dynamic analyses of seismic response of eccentrically braced frames. It is shown that in the upper floors only multimodal pushover procedures provide results close to the dynamic profile, while the proposed load patterns are always conservative in the lower floors. They over-estimate the seismic response less than the uniform distribution, representing a reliable alternative to the uniform or more sophisticated adaptive procedures proposed by seismic codes. © 2008 American Institute of Physics.
Forces and flow structures evolution on a car body in a sudden crosswind
2014
A vehicle driver is commonly exposed to strong side air flows, for example when passing through a wind gust. The aerodynamic efforts generated in these situations may induce undesired lateral deviations, which can lead to dramatic effects, if the driver is surprised. In order to simulate a sudden yaw angle change on a moving vehicle, a double wind tunnel facility, adapted from the one of Ryan, Dominy, 2000. Wake Surveys Behind a Passenger Car Subjected to a Transient Cross-wind Gust. SAE Technical Paper No. 2000-01-0874 is developed. Two Windsor car body models, differing from their rear geometry, are analysed. The transient evolution of the side force and yaw moment aerodynamic coefficient…
Definition of a laboratory optimization protocol for road bitumen improved with recycled tire rubber
2012
Abstract Bearing in mind the need to answer one of the most frequent needs for civil construction, in general, and major project such as road infrastructures in particular, this paper presents the results of a laboratory experimental study in order to evaluate the performance improvement that is possible to achieve when modifying road bitumen with CRM (Crumb Rubber Modifier) from discarded tire rubber (TR), using a Wet Process. The environmental advantage is double, since the aim of the research is to obtain high performance road bitumen thanks to the re-use of a discarded material, such as the rubber tires, which otherwise would be dumped in scrap-yard. In particular, this experimental stu…
Cogeneration plant in a pasta factory: Energy saving and environmental benefit
2007
Abstract Italy produces approximately 4,520,000 tons of pasta annually, which is about 67% of its total productive potential. As factories need electric and thermal energy simultaneously, combined heat and power (CHP) systems are the most suitable. This paper describes a feasibility study of a CHP plant in a pasta factory in Italy while analyzing energy saving and environmental benefits. Commercially available CHP systems suitable for the power range of energy demand in pasta production use reciprocating engines or gas turbines. This study demonstrates how their use can reduce both energy costs and CO2 equivalent greenhouse gas emission in the environment. An economic analysis was performed…
Recycled Tyre Rubber Modified Bitumens for road asphalt mixtures: A literature review
2013
AbstractNowadays, only a small percentage of waste tyres are being land-filled. The Recycled Tyre Rubber is being used in new tyres, in tyre-derived fuel, in civil engineering applications and products, in moulded rubber products, in agricultural uses, recreational and sports applications and in rubber modified asphalt applications. The benefits of using rubber modified asphalts are being more widely experienced and recognized, and the incorporation of tyres into asphalt is likely to increase. The technology with much different evidence of success demonstrated by roads built in the last 40years is the rubberised asphalt mixture obtained through the so-called “wet process” which involves the…
Expected principal stress directions under multiaxial random loading. Part II: Numerical simulation and experimental assessment through the weight fu…
1999
In Part I of the present work, the theoretical aspects of a proposed procedure to determine the expected principal stress directions under multiaxial random loading have been discussed. This procedure consists of averaging the instantaneous values of the three Euler angles through weight functions. In Part II here, a numerical simulation is presented to illustrate the above theoretical method. As an example, the algorithm proposed is applied to some experimental biaxial in- and out-of-phase stress states to assess the correlation between the expected principal stress directions and the position of the experimental fatigue fracture plane for such tests.
Re-analysis of fatigue data for welded joints using the notch stress approach
2010
Abstract Experimental fatigue data for welded joints have been collected and subjected to re-analysis using the notch stress approach according to IIW recommendations. This leads to an overview regarding the reliability of the approach, based on a large number of results (767 specimens). Evidently, there are some limitations in the approach regarding mild notch joints, such as butt joints, which can be assessed non-conservatively. In order to alleviate this problem, an increased minimum notch factor of Kw ⩾ 2.0 is suggested instead of the current recommendation of Kw ⩾ 1.6. The data for most fillet-welded joints agree quite well with the FAT 225 curve; however a reduction to FAT 200 is sugg…
Numerical prediction of the shear response of semi-prefabricated steel-concrete trussed beams
2016
Abstract In this study, the shear behavior of hybrid steel-trussed-concrete beams (HSTCBs) realized with prefabricated steel trusses embedded into a concrete core cast in situ, is investigated by means of Finite Element (FE) numerical simulations. HSTCBs do not behave as classical RC elements nor composite beams. Up to now, there are not specific design criteria in the building codes and the calculation of this type of beams is conducted by means of design-by-testing procedures. The knowledge of the material behavior as well as the understanding of the interaction between materials in contact is the first requirement for the definition of proper design procedures and calculation methods for…
Material characteristics in the analysis of heated steel beams
1989
Beam fire tests are expensive and complicated. They may be replaced by calculations of the heated beam deflection by means of the method presented in this paper. The following material characteristics in the analysis of the deflection of beams during fire may be taken as fundamental: the steel creep characteristic at elevated temperatures, the modulus of elasticity and the coefficient of thermal expansion. According to the yield hinge theory, the yield stress is the criterion of failure of steel beams in fire. On the other hand, in the analysis of the deflection of the heated steel beams the influence of the yield stress is very small. The influence of the respective material characteristic…