The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform

Oreste S Bursi - One of the best experts on this subject based on the ideXlab platform.

  • Seismic performance and fragility functions of a 3D Steel-Concrete Composite Structure made of high-strength steel
    Engineering Structures, 2018
    Co-Authors: Nicola Tondini, Gabriele Zanon, Raffaele Pucinotti, R. Di Filippo, Oreste S Bursi
    Abstract:

    Abstract This paper provides insight into a probabilistic seismic demand analysis of a Steel-Concrete Composite Structure made of a novel type of high-strength steel moment resisting frame, to be used either in a seismic risk assessment or a fully probabilistic Performance-Based Earthquake Engineering (PBEE) framework. The application of the PBEE methodology with a full probabilistic character is able to rigorously evaluate the seismic risk to which a Structure may be exposed, as well as to quantify economic losses, including both direct -repair, reconstruction costs, etc.- and indirect costs -downtimes, etc.-. In this respect, the knowledge of seismic fragility functions is paramount. Moreover, due to the dynamic complexity of the examined Structure caused by irregularity in elevation and different lateral-force resisting systems in the two main directions -moment resisting frames (MRFs) and concrete shear walls- the seismic behaviour is not straightforward to foresee. Therefore, two separate 2D analyses along the building main directions may not suffice to identify the actual dynamic response and, consequently, a 3D comprehensive probabilistic seismic demand analysis was performed by taking into account the earthquake incident angle. In order to exploit the inherent overstrength of non-dissipative members, consistently with the capacity design philosophy, the Structure, that is a representative example of a realistic office building, is characterised by a newly-conceived type of moment resisting frame made of high-strength steel circular columns filled of concrete and of mild steel beams. In this respect, a nonlinear 3D FE model was developed and calibrated on experimental tests performed on both beam-to-column and column-base joints that formed MRFs. A multiple incremental dynamic analysis (MIDA) was then performed with two groups of bespoke accelerograms characterised, on one hand, by large magnitude and large distance and, on the other hand, by near-source effects. The earthquake incidence angle was also considered and, to decrease the number of simulations, the accelerogram-incident angle pairs were selected by means of the Latin hypercube sampling (LHS) method. The relevant seismic analyses highlighted the need to include the incident angle to better characterise its dynamic behaviour. Hence, the seismic fragility functions were built both for damage and collapse limit states considering both the maximum interstorey drift ratio as engineering demand parameter and different intensity measures as well as the incident angle randomness. The results showed that peak ground displacement entails a more efficient probabilistic model because the dominant structural dynamic behaviour was governed by MRFs characterised by fairly long periods.

  • Finite element model updating of a steel - Concrete Composite moment-resisting Structure with partial strength joints
    Key Engineering Materials, 2007
    Co-Authors: Oreste S Bursi, A. Savadkoohi, Michael Molinari, Daniele Zonta
    Abstract:

    Dynamic and static identification of a full scale moment-resisting Steel-Concrete Composite Structure with partial strength joints that was tested by means of the pseudo-dynamic testing technique at the ELSA laboratory of the Joint Research Centre at Ispra, Italy, is the subject of this paper. The Structure was subjected to pseudo-dynamic and dynamic tests at different damage and peak ground acceleration levels; and the results were used for identifying the behaviour of the Structure. Two and three-dimensional refined finite element models of the Structure accompanied by a robust nonlinear optimization method, the Powell's Dog Leg method, were updated in order to reproduce in an optimal fashion the experimental static and dynamic behaviour of the Structure.

Daniele Zonta - One of the best experts on this subject based on the ideXlab platform.

  • Finite element model updating of a steel - Concrete Composite moment-resisting Structure with partial strength joints
    Key Engineering Materials, 2007
    Co-Authors: Oreste S Bursi, A. Savadkoohi, Michael Molinari, Daniele Zonta
    Abstract:

    Dynamic and static identification of a full scale moment-resisting Steel-Concrete Composite Structure with partial strength joints that was tested by means of the pseudo-dynamic testing technique at the ELSA laboratory of the Joint Research Centre at Ispra, Italy, is the subject of this paper. The Structure was subjected to pseudo-dynamic and dynamic tests at different damage and peak ground acceleration levels; and the results were used for identifying the behaviour of the Structure. Two and three-dimensional refined finite element models of the Structure accompanied by a robust nonlinear optimization method, the Powell's Dog Leg method, were updated in order to reproduce in an optimal fashion the experimental static and dynamic behaviour of the Structure.

Yang Yun-biao - One of the best experts on this subject based on the ideXlab platform.

  • A FINITE ELEMENT METHOD FOR VERTICAL MECHANICS ANALYSIS OF Steel-Concrete Composite Structure IN PYLON CABLE ANCHOR ZONE OF LONG SPAN CABLE-STAYED BRIDGE
    Engineering mechanics, 2020
    Co-Authors: Yang Yun-biao
    Abstract:

    In Steel-Concrete Composite Structure of pylon cable anchor zone in cable-stayed bridge, most of vertical component of applied cable force transfers from steel anchor box to concrete walls through shear studs, but the mechanism of vertical force transfer is complicated and remains unaddressed. After introducing the analytical continuum method, this paper simplifies the analysis problems and obtains the fundamental differential equation which can reveal the vertical mechanics of the Composite Structure, and then deduces the element stiffness matrix and load vectors for the finite element solution of analysis. This paper also considers the effect of shrinkage and creep on the Composite Structure at different construction stages in order to obtain best analysis results to describe the real structural behavior. Through an engineering design example, the method proposed in this paper is verified by a comparison of its calculation results with those obtained from complicated 3D finite element method. The proposed method is simpler and more efficient than 3D finite element method, and can be used in structural analysis.

Chen Qu - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Steel-Concrete Composite Structure Element
    Applied Mechanics and Materials, 2011
    Co-Authors: Chang Zhou Dong, Chen Qu
    Abstract:

    The Structure of eccentric degenerated 3-D shell element of thin-wall steel tube concrete Composite Structure and the connection with 3-D block isoparametric element has been discussed using finite element method. Without considering the intensity limit of delamination damage of the two materials, an integrated stiffness matrix is formed with the combination of stiffness matrix of steel-wall shell element and that of concrete spatial block element. In order to make the superposition rule may be used at the joint of 8-node curved shell element and 20-node block element, an eccentric 8-node shell element is constructed.

J Rodrigues - One of the best experts on this subject based on the ideXlab platform.

  • Dynamic tests of the Santar�m cable-stayed bridge
    Proceedings of the International Modal Analysis Conference - IMAC, 2001
    Co-Authors: J Rodrigues
    Abstract:

    The Santar�m cable-stayed bridge is a road bridge that crosses the\nTagus River near the city of Santar�m. It is located about 3.5 km\ndownstream from the old steel truss bridge (D. Lu�s bridge), built\nmore than 100 years ago, and that was already insufficient for the\nincreasing traffic and loads that had to cross it. The new bridge\nhas a total length of 570 m with a central span of 246 m. The bridge\ndeck has a cross-section formed by a 10.0 m by 2.5 m hollow rectangular\nshape caisson with an upper lateral slab and pre-cast concrete bracing's.\nThe two masts have a height of 50 m above the deck and are in reinforced\nconcrete up to the level of the first cables, and from there on have\na Steel-Concrete Composite Structure. Before being opened to the\ntraffic, the new bridge was subjected to static and dynamic load\ntests. This paper describes the dynamic tests that were conducted\non the Structure and that consisted in vibration measurements with\nthe bridge being crossed by loaded trucks and also in tests with\nthe trucks passing over a wood plank in order to apply an impulsive\nload to the Structure. The paper describes the testing procedure\nand the analysis techniques that were used to process the measured\naccelerations. The characteristics of 32 natural vibration modes\nof the bridge are estimated from the tests data and are compared\nwith the ones evaluated with a finite element model.

  • Dynamic tests of the Santarem cable-stayed bridge
    Proceedings of Imac-Xix: A Conference on Structural Dynamics Vols 1 and 2, 2001
    Co-Authors: J Rodrigues
    Abstract:

    The Santarem cable-stayed bridge is a road bridge that crosses the Tagus River near the city of Santarem. It is located about 3.5 km downstream from the old steel truss bridge (D. Luis bridge), built more than 100 years ago, and that was already insufficient for the increasing traffic and loads that had to cross it. The new bridge has a total length of 570 m with a central span of 246 m. The bridge deck has a cross-section formed by a 10.0 m by 2.5 m hollow rectangular shape caisson with an upper lateral slab and pre-cast concrete bracing's. The two masts have a height of 50 m above the deck and are in reinforced concrete up to the level of the first cables, and from there on have a Steel-Concrete Composite Structure. Before being opened to the traffic, the new bridge was subjected to static and dynamic load tests. This paper describes the dynamic tests that were conducted on the Structure and that consisted in vibration measurements with the bridge being crossed by loaded trucks and also in tests with the trucks passing over a wood plank in order to apply an impulsive load to the Structure. The paper describes the testing procedure and the analysis techniques that were used to process the measured accelerations. The characteristics of 32 natural vibration modes of the bridge are estimated from the tests data and are compared with the ones evaluated with a finite element model.