Probabilistic Structural System Response to Differential Settlement Resulting from Spatially Variable Soil

Author(s):  
Armin W. Stuedlein ◽  
Jonathan C. Huffman ◽  
Andre R. Barbosa ◽  
Andre F. V. Belejo
ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 155
Author(s):  
Zacharias Vangelatos ◽  
Michail Delagrammatikas ◽  
Olga Papadopoulou ◽  
Charalampos Titakis ◽  
Panayota Vassiliou

<p class="Abstract">Finite element analysis is employed to investigate the mechanical behaviour and failure scenarios of the marble block–steel clamp ancient masonry system utilised in the Parthenon (Athens Acropolis) under static loading analysis. The input data for the model are acquired by the laboratory testing of early 20th century restoration steel clamps, such as through tensile strength measurements and metallography, as well as bibliographic sources from various scientific fields (i.e. material properties, archaeometry, restoration, structural engineering and geology). Two different embedding materials (Portland cement mortar and lead), used for the nesting of the clamps, are examined under bending or stretching, induced by acceleration forces. The conservation status of the materials is taken into account by employing an intrinsic stress, as is the case when corrosion products build up in a confined space. The aim of this work is to provide a tool for the assessment of the conservation potential of the marble blocks in parts of the monument that require specific attention. Simulation results indicate the resilience of the Parthenon’s structural system under most examined scenarios and highlight the importance of intrinsic stresses, the existence of which may lead to the fracture of the marble blocks under otherwise harmless loading conditions.</p>


2011 ◽  
Vol 291-294 ◽  
pp. 2115-2118 ◽  
Author(s):  
Bing Li ◽  
Yu Lan Wei ◽  
Shou Xin Zhu ◽  
Yu Qing Zheng

The methodologies and application of hybrid multi-mode positive impulses input shaping of a 3-DOF flexible parallel manipulator in this paper. First, the structural system and the dynamic equations are expressed for a 3-DOF manipulator. Second, the hybrid multi-mode positive impulses input shaping is introduced to reduce the residual vibration of the multi-mode system or to decrease the time-delay of the system response at the same time. The theory of the hybrid multi-mode positive impulses input shapers are presented, and the hybrid two-mode positive impulses input shapers of a 3-DOF manipulator are established and compared with the classic multi-mode positive impulses input shapers. Finally, the numerical simulations are made, and the robust of the input shapers are presented and compared.


2022 ◽  
pp. 136943322110523
Author(s):  
Gökhan Çetin ◽  
Mohammed S Fadali ◽  
Gökhan Pekcan

This paper proposes a dissipative resilient observer and controller (DROC) design for a network controlled system (NCS) that handles faults, implementation errors, or cyberattacks that can be modeled as bounded controller or observer gain perturbations. It presents linear matrix inequality (LMI) conditions for the robust stability of the system in the presence of bounded perturbations in the observer and controller. Furthermore, a new LMI-based time-delay control (TDC) algorithm that mitigates the effects of perturbations due to time-delays in the NCS is introduced. The robust methodology is applied to active control of a scaled model of a structural system equipped with an active mass driver system. The results demonstrate that the proposed methodology is robust and ensures stable system response due to various types of earthquake base excitations.


2012 ◽  
Vol 549 ◽  
pp. 816-820 ◽  
Author(s):  
Qing Huang ◽  
Dan Zhang ◽  
Bing Li ◽  
Yu Lan Wei

The methodologies and application of multiple-mode negative impulses input shaping of a 3-DOF parallel manipulator with flexible intermediate linkages are presented in this paper. First, the structural system and the dynamic equations are expressed for a 3-DOF manipulator. Second, the multiple-mode negative impulses input shaping is introduced to reduce the residual vibration of the multiple-mode system and decrease the delay time of the system response at the same time. Finally, the theory of the multiple-mode ZV, ZVD and EI negative impulses input shapers are presented, and the two-mode negative impulses input shapers of a 3-DOF manipulator are established and compared with the positive impulses input shapers.


2019 ◽  
Vol 8 (4) ◽  
pp. 8100-8106

Tubular structural system is a 3 dimensional space structure comprises of 3, 4 or possibly more frames, braced frames or shear walls joined at or near their edges to form a vertical tube like structural system which is capable of resisting lateral forces in any direction by cantilevering from the foundation. Tubular tall building structures have started becoming an integral part of the building scenario in developed countries. They provide various advantages over a conventional tall building in terms of flexibility of interior spacing, better utilization of material and hence lesser cost of construction. Therefore studies on various parameters that influence the serviceability of such structure is beneficial in the long run. One such parameter is the differential settlement of tubular structures is studied under this work. This research work will shed some light on the influence of differential settlement on the tubular structures. The differential settlement that would occur on four separate G+60 tubular tall structures under different framed conditions is determined using a structural analysis and design software and thereby observed that there was a gradual increase from zero at the base of structure in fixed supports whereas in spring supports there was a settlement at the base of structure. From the analysis of different tube structures like framed tube, braced tube, bundled tube and tube in tube structures, it was observed that there was a certain percentage increase in the settlement of top storey with spring support when compared to that of fixed support. Compared to other tube structures, the framed tube structure exhibited a better performance in settlement under both the support conditions.


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