scholarly journals Comparison of Two Mechanics-Based Methods for Simplified Structural Analysis in Vulnerability Assessment

2008 ◽  
Vol 2008 ◽  
pp. 1-19 ◽  
Author(s):  
H. Crowley ◽  
B. Borzi ◽  
R. Pinho ◽  
M. Colombi ◽  
M. Onida
Keyword(s):  
Structural Analysis ◽  
Vulnerability Assessment ◽  
Ground Motions ◽  
Structural Models ◽  
Assessment Methods ◽  
Static Response ◽  
Nonlinear Analyses ◽  
Damage Data ◽  
Nonlinear Static ◽  
Observed Damage

Analytical vulnerability assessment methods should ideally be validated or verified by comparing their damage predictions with actual observed damage data. However, there are a number of difficulties related to the comparison of analytical damage predictions with observed damage; for example, there are large uncertainties related to the prediction of the ground motions to which the damaged buildings have been subjected. Until such problems can be resolved, it is worthwhile considering the mechanics of simplified analytical vulnerability assessment methods and validating this part of the methodology through comparisons with detailed structural models. This paper looks at two mechanics-based vulnerability assessment methods (DBELA and SP-BELA) and compares the nonlinear static response predicted with these methods with finite elements-based nonlinear analyses of prototype buildings. A comparison of the predicted response of urban populations of buildings using the two methods is then carried out, and the influence of these differences on vulnerability curves is studied.

scholarly journals Nonlinear static response of low-aspect-ratio inverted flags subjected to a steady flow

2018 ◽  
Vol 83 ◽  
pp. 413-428 ◽  
Author(s):  
Mohammad Tavallaeinejad ◽  
Michael P. Païdoussis ◽  
Mathias Legrand
Keyword(s):  
Aspect Ratio ◽  
Steady Flow ◽  
Static Response ◽  
Low Aspect Ratio ◽  
Nonlinear Static

scholarly journals Macromolecular Nanocrystal Structural Analysis with Electron and X-Rays: A Comparative Review

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3490
Author(s):  
Krishna P. Khakurel ◽  
Borislav Angelov ◽  
Jakob Andreasson
Keyword(s):  
Structural Analysis ◽  
Structural Models ◽  
X Rays ◽  
High Quality ◽  
X Ray ◽  
Detection Techniques ◽  
Comparative Review

Crystallography has long been the unrivaled method that can provide the atomistic structural models of macromolecules, using either X-rays or electrons as probes. The methodology has gone through several revolutionary periods, driven by the development of new sources, detectors, and other instrumentation. Novel sources of both X-ray and electrons are constantly emerging. The increase in brightness of these sources, complemented by the advanced detection techniques, has relaxed the traditionally strict need for large, high quality, crystals. Recent reports suggest high-quality diffraction datasets from crystals as small as a few hundreds of nanometers can be routinely obtained. This has resulted in the genesis of a new field of macromolecular nanocrystal crystallography. Here we will make a brief comparative review of this growing field focusing on the use of X-rays and electrons sources.

Yield Point Spectra for Seismic Design and Rehabilitation

2000 ◽  
Vol 16 (2) ◽  
pp. 317-335 ◽  
Author(s):  
Mark Aschheim ◽  
Edgar F. Black
Keyword(s):  
Yield Point ◽  
Seismic Design ◽  
Ground Motions ◽  
Existing Structures ◽  
Intuitive Appeal ◽  
Forward Directivity ◽  
Capacity Spectrum ◽  
Long Duration ◽  
Nonlinear Static ◽  
Strength And Stiffness

A new spectral representation of seismic demand is described for use in the seismic design of new structures and in the evaluation and rehabilitation of existing structures. Yield Point Spectra (YPS) retain the intuitive appeal of the Capacity Spectrum Method (Freeman 1978) and join the Nonlinear Static Procedures of FEMA 273/274 (1997) and ATC 40 (1996) for use in estimating displacement demands. YPS also may be used to establish admissible combinations of strength and stiffness for the design of new structures to limit system ductility and drift to arbitrary values. Graphical procedures allow admissible design regions to be established to satisfy multiple performance objectives. YPS computed for 15 ground motions classified as Short Duration, Long Duration, or as containing near-fault Forward Directivity pulses are presented for bilinear and stiffness-degrading hysteretic models.

Effect of Bolt Slippage and Joint Eccentricity on the Response of Lattice Structure with Non-Uniform Settlement

2013 ◽  
Vol 483 ◽  
pp. 289-296 ◽  
Author(s):  
Hui Wu Zhang ◽  
Peng Wang ◽  
Hai Bo Chen
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Lattice Structure ◽  
Static Response ◽  
Bolted Connection ◽  
Structure Deformation ◽  
Element Simulation ◽  
Joint Connection ◽  
Internal Forces ◽  
Simulation Results

Lattice transimission towers are commonly made of angles bolted together directly or through gussets. And angle members are usually subjected to high axial force with eccentricity. Conventional structural analysis softwares solve such problems with the assumption of regarding the bolted connection as a rigid joint connection and ignored the effect of joint eccentricity. Thus the calculated internal forces of the structure members are bigger than those of real measurements, and the calculated structure deformation are smaller than the experimental ones under the same load. The main reasons for the discrepancy between the experimental results and the analytical solutions are bolt slippage and joint eccentricity. In this paper, the displacement-load curves of the bolted connections are introduced into the finite element simulation, revealing the effect of bolt slippage on the static response of lattice structure. The simulation results show that the bolt slippage causes the redistribution of the member internal forces of the lattice structure and increases the displacement of the lattice structure. The proposed algorithm and simulation results would provide good reference for further engineering applications.

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