AN ENERGY-BASED FORMULATION FOR FIRST-AND MULTIPLE-MODE NONLINEAR STATIC (PUSHOVER) ANALYSES

2004 ◽  
Vol 8 (1) ◽  
pp. 69-88 ◽  
Author(s):  
ENRIQUE HERNÁNDEZ-MONTES ◽  
OH-SUNG KWON ◽  
MARK A. ASCHHEIM
Keyword(s):  
Multiple Mode ◽  
Nonlinear Static

Modelling and control of an alkaline water electrolysis process

2018 ◽  
Vol 1 (2) ◽  
pp. 9-14
Author(s):  
Marisol Cervantes-Bobadilla ◽  
Ricardo Fabricio Escobar Jiménez ◽  
José Francisco Gómez Aguilar ◽  
Tomas Emmanuel Higareda Pliego ◽  
Alberto Armando Alvares Gallegos
Keyword(s):  
Process Model ◽  
Water Electrolysis ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
Electrolysis Process ◽  
Linear Dynamic ◽  
Energy Current ◽  
Identification Technique ◽  
Nonlinear Static ◽  
And Control

In this research, an alkaline water electrolysis process is modelled. The electrochemical electrolysis is carried out in an electrolyzer composed of 12 series-connected steel cells with a solution 30% wt of potassium hydroxide. The electrolysis process model was developed using a nonlinear identification technique based on the Hammerstein structure. This structure consists of a nonlinear static block and a linear dynamic block. In this work, the nonlinear static function is modelled by a polynomial approximation equation, and the linear dynamic is modelled using the ARX structure. To control the current feed to the electrolyzer an unconstraint predictive controller was implemented, once the unconstrained MPC was simulated, some restrictions are proposed to design a constrained MPC (CMPC). The CMPC aim is to reduce the electrolyzer's energy consumption (power supply current). Simulation results showed the advantages of using the CMPC since the energy (current) overshoots are avoided.

scholarly journals Failure Analysis of Apennine Masonry Churches Severely Damaged during the 2016 Central Italy Seismic Sequence

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 58 ◽  
Author(s):  
Francesco Clementi
Keyword(s):  
Case Studies ◽  
Central Italy ◽  
Numerical Data ◽  
Sensitivity Study ◽  
Nonlinear Material ◽  
Seismic Sequence ◽  
Nonlinear Approach ◽  
Nonlinear Static ◽  
Masonry Churches ◽  
Global And Local

This paper presents a detailed study of the damages and collapses suffered by various masonry churches in the aftermath of the seismic sequence of Central Italy in 2016. The damages will first be analyzed and then compared with the numerical data obtained through 3D simulations with eigenfrequency and then nonlinear static analyses (i.e., pushover). The main purposes of this study are: (i) to create an adequately consistent sensitivity study on several definite case studies to obtain an insight into the role played by geometry—which is always unique when referred to churches—and by irregularities; (ii) validate or address the applicability limits of the more widespread nonlinear approach, widely recommended by the Italian Technical Regulations. Pushover analyses are conducted assuming that the masonry behaves as a nonlinear material with different tensile and compressive strengths. The consistent number of case studies investigated will show how conventional static approaches can identify, albeit in a qualitative way, the most critical macro-elements that usually trigger both global and local collapses, underlining once again how the phenomena are affected by the geometry of stones and bricks, the texture of the wall face, and irregularities in the plan and elevation and in addition to hypotheses made on the continuity between orthogonal walls.

Secure Multiple-Mode OFDM With Index Modulation

2020 ◽  
Author(s):  
Yuankun Tang ◽  
Miaowen Wen ◽  
Shahid Mumtaz ◽  
Daniel Benevides da Costa ◽  
Mohsen Guizani
Keyword(s):  
Multiple Mode ◽  
Index Modulation

scholarly journals Muscle-fiber array inspired, multiple-mode, pneumatic artificial muscles through planar design and one-step rolling fabrication

2021 ◽  
Author(s):  
Jiang Zou ◽  
Miao Feng ◽  
Ningyuan Ding ◽  
Peinan Yan ◽  
Haipeng Xu ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Artificial Muscles ◽  
Fiber Array ◽  
Fiber Arrays ◽  
Multiple Mode ◽  
Pneumatic Artificial Muscles ◽  
Pipe Line ◽  
One Step ◽  
Robotic Applications ◽  
Compliant Electrodes

Abstract Although the advances in artificial muscles enable creating soft robots with biological dexterity and self-adaption in unstructured environments, producing scalable artificial muscles with multiple-mode actuations is still elusive. Inspired by muscle-fiber arrays in muscular hydrostats, we present a class of versatile artificial muscles, called MAIPAMs (Muscle-fiber Array Inspired Pneumatic Artificial Muscles), capable of multiple-mode actuations (such as parallel elongation-bending-spiraling actuations, parallel 10 bending actuations, and cascaded elongation-bending-spiraling actuations). Our MAIPAMs mainly consist of active 3D elastomer-balloon arrays reinforced by a passive elastomer membrane, which is achieved through a planar design and one-step rolling fabrication approach. We introduce the prototypical designs of MAIPAMs and demonstrate their muscle-mimic structures and versatility, as well as their scalable ability to integrate flexible while un-stretchable layers for contraction and twisting actuations and compliant electrodes for self-sensing. We further demonstrate that this class of artificial muscles shows promising potentials for versatile robotic applications, such as carrying a camera for recording videos, gripping and manipulating objects, and climbing a pipe-line.

scholarly journals Displacement Demand for Nonlinear Static Analyses of Masonry Structures: Critical Review and Improved Formulations

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 118
Author(s):  
Gabriele Guerrini ◽  
Stylianos Kallioras ◽  
Stefano Bracchi ◽  
Francesco Graziotti ◽  
Andrea Penna
Keyword(s):  
Time History ◽  
Nonlinear Static Analysis ◽  
Equivalent Linearization ◽  
Eurocode 8 ◽  
Masonry Structures ◽  
Equivalent Viscous Damping ◽  
Inelastic Displacement ◽  
N2 Method ◽  
Nonlinear Static ◽  
Nonlinear Time History

This paper discusses different formulations for calculating earthquake-induced displacement demands to be associated with nonlinear static analysis procedures for the assessment of masonry structures. Focus is placed on systems with fundamental periods between 0.1 and 0.5 s, for which the inelastic displacement amplification is usually more pronounced. The accuracy of the predictive equations is assessed based on the results from nonlinear time-history analyses, carried out on single-degree-of-freedom oscillators with hysteretic force–displacement relationships representative of masonry structures. First, the study demonstrates some limitations of two established approaches based on the equivalent linearization concept: the capacity spectrum method of the Dutch guidelines NPR 9998-18, and its version outlined in FEMA 440, both of which overpredict maximum displacements. Two codified formulations relying on inelastic displacement spectra are also evaluated, namely the N2 method of Eurocode 8 and the displacement coefficient method of ASCE 41-17: the former proves to be significantly unconservative, while the latter is affected by excessive dispersion. A non-iterative procedure, using an equivalent linear system with calibrated optimal stiffness and equivalent viscous damping, is then proposed to overcome some of the problems identified earlier. A recently developed modified N2 formulation is shown to improve accuracy while limiting the dispersion of the predictions.

Sign in / Sign up

Export Citation Format

Share Document