scholarly journals Seismic Model Parameter Optimization for Building Structures

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1980
Author(s):  
Lengyel Károly ◽  
Ovidiu Stan ◽  
Liviu Miclea
Keyword(s):  
Optimization Algorithms ◽  
Building Structures ◽  
Lateral Loads ◽  
Nonlinear Dynamic Model ◽  
Structural Dynamic ◽  
De Algorithm ◽  
Building Behavior ◽  
Mass Spring ◽  
Performance Results ◽  
Model Parameter Optimization

Structural dynamic modeling is a key element in the analysis of building behavior for different environmental factors. Having this in mind, the authors propose a simple nonlinear model for studying the behavior of buildings in the case of earthquakes. Structural analysis is a key component of seismic design and evaluation. It began more than 100 years ago when seismic regulations adopted static analyzes with lateral loads of about 10% of the weight of the structure. Due to the dynamics and non-linear response of the structures, advanced analytical procedures were implemented over time. The authors’ approach is the following: having a nonlinear dynamic model (in this case, a multi-segment inverted pendulum on a cart with mass-spring-damper rotational joints) and at least two datasets of a building, the parameters of the building’s model are estimated using optimization algorithms: Particle Swarm Optimization (PSO) and Differential Evolution (DE). Not having much expertise on structural modeling, the present paper is focused on two aspects: the proposed model’s performance and the optimization algorithms performance. Results show that among these algorithms, the DE algorithm outperformed its counterpart in most situations. As for the model, the results show us that it performs well in prediction scenarios.

Transient Analysis of Coupled Longitudinal and Transverse Vibration of Large Container Ship Propulsion Shafting

2015 ◽  
Author(s):  
Qianwen Huang ◽  
Cong Zhang ◽  
Jia Liu ◽  
Xinping Yan
Keyword(s):  
Transverse Vibration ◽  
Lateral Loads ◽  
Simulation Technology ◽  
Structural Dynamic ◽  
Coupled Vibrations ◽  
Marine Propulsion ◽  
Safety And Reliability ◽  
Structural Dynamic Characteristics ◽  
Coupling Dynamics ◽  
Large Container

Marine propulsion shafting connects between the host and the propellers to promote the movement of ship, varieties of Different coupled vibrations forms produce different kinds of coupled vibrations, the coupled vibration of propulsion shafting poses serious threat to the safety and reliability of the sailing of ship. Considering the uncertainty of the experimental test for propulsion shafting, the simulation technology of coupling dynamics becomes particularly significant. This paper introduces a finite element method in numerical modeling and simulation technology of coupled dynamics for propulsion shafting. Combined with the theory of coupled mechanics, the coupled longitudinal and transverse dynamic response of propulsion shafting under the condition of no-coupling and the coupled are compared. The structural dynamic characteristics of longitudinal and lateral loads are discussed respectively. Analysis shows that different forms of excitation have certain effects on the performance of coupled longitudinal and transverse vibration for propulsion shafting. The research aims to reveal the basic principle of coupled longitudinal and transverse vibration for marine propulsion shafting to improve the safety and reliability of the sailing performance of the ships.

Development of a Drift Protocol for Seismic Performance Evaluation considering a Damage Index Concept

2011 ◽  
Vol 27 (4) ◽  
pp. 1049-1076 ◽  
Author(s):  
Tara C. Hutchinson ◽  
Jian Zhang ◽  
Charles Eva
Keyword(s):  
Structural Damage ◽  
Drift Time ◽  
Damage Index ◽  
Building Structures ◽  
Structural Dynamic ◽  
Work Demand ◽  
Ground Motion Selection ◽  
Seismic Performance Evaluation ◽  
Window Systems ◽  
Time Histories

In this paper, two new protocols are proposed, developed based on cycle counting and forward ordering of interstory drift time histories for representative mid- and low-rise building structures. The proposed drift protocols involve: (i) ground motion selection and scaling, (ii) representative building selection and modeling, (iii) nonlinear structural dynamic response calculations, and (iv) modified simple range counting to derive amplitude count information. In this work, demand sequencing is considered. This aspect is important, as excursions with the same amplitude occurring at different times will contribute differently to structural damage; therefore, they are sequenced and weighted differently. For this purpose, a damage index concept is used to evaluate each excursion and define instantaneous weight factors. The protocols are applied to a series of in-plane racking tests on window systems. Damage modes and associated drift limits are compared for the proposed protocols as well as several others, namely; a monotonic (static) push, the “Crescendo” (dynamic) loading protocol, and the FEMA 461 (quasistatic) loading protocol.

Simplified Dynamic Finite-Element Analysis for Three-Dimensional Pile-Grouped-Raft-High-Rise Buildings

2008 ◽  
Vol 400-402 ◽  
pp. 613-619
Author(s):  
Hui Xiong ◽  
Shou Ping Shang ◽  
Liang Huang
Keyword(s):  
Finite Element ◽  
Structural Engineering ◽  
Computational Cost ◽  
Time History ◽  
Pile Group ◽  
Element Analysis ◽  
Structural Dynamic ◽  
Shell Elements ◽  
High Rise ◽  
Mass Spring

Combined with the respective advantages in S-R(Sway-Rocking) impedance concept and finite-element method, a simplified 3D structural dynamic FEM considering composite pile-group-soil effects is presented. The structural members including piles are modeled by spacial beam or shell elements, and raft-base is divided into thick-shell elements with its spring-dashpot boundary coefficient obtained by impedance backcalculated. The mass-spring elements for soil between piles are set to simulate vertical, horizontal pile-group effects by strata-equivalent approach. The soil beside composite body is separated into near-field and far-field parts. The former is modeled by nonlinear spring-dashpot elements based on Winkler’s hypothesis, while the latter is modeled by a series of linear mass-spring-dashpots. With the effects of boundary track forces and energy radiation, the presented model enables researchers to conduct the time-domain nonlinear analysis in a relatively simple manner which avoids sophisticated boundary method and solid-element mesh bringing with tremendous computational cost. The seismic effect on dynamic interaction of pile-soil-complicated structures would be efficiently annotated from two structural engineering and geotechnical engineering aspects and the numerical calculation effort would be drastically decreased too. The complete procedure is mainly performed using the parametric design language assembled in the Finite Element Code Ansys. With the dynamic analysis of foundation and superstructure for a pile-supported 15-storey building, the influence of the participant effect on structural dynamic response will be depicted by various dynamic parameters of pile-soil-raft foundation in detail. Not only do the results have an agreement with some conclusions drawn by the general interaction theory, but also certain of phenomena which would be disagree with that by general analysis is involved. Even with the finite-element meshes for 68 piles, the time-history analysis procedure for PGSS (Pile-Group-Soil-Superstructure) system and the qualitative evaluation with various SSI parameters can be also fulfilled efficiently and rapidly by presented means. These results may be of help to the designers to quickly assess the significance of interaction effect for the high-rise buildings resting on any type or layout of pile-group foundation.

Experimental Study on Blast Resistant Structure with Composite Protection Layer

2011 ◽  
Vol 250-253 ◽  
pp. 2866-2871 ◽  
Author(s):  
Run Lin Yang ◽  
Hai Guo
Keyword(s):  
Steel Plate ◽  
Composite Layer ◽  
Experimental Tests ◽  
Building Structures ◽  
Protection Measure ◽  
Structural Dynamic ◽  
Flexible Material ◽  
Protection Layer ◽  
Composite Protection ◽  
Resistant Structure

Since the terrorist attacks have increased over the world in recent years, blast-resistant protection of building structures has received considerable attention. The rigid and flexible composite protection layer as a new protection measure was examined through the method of experimental tests in this paper. Two sealed steel boxes were selected for the testing, one with the rigid and flexible composite layer, while the other without any protection. The rubber was selected as the flexible material while the steel plate is selected as the rigid material. The effectiveness of the composite layer under different explosive loadings was investigated. By comparing the structural strains, the experimental results show that the rigid and flexible layer can suppress the structural dynamic response obviously, and the blast-resistant effect of the composite layer will be increased further with increase of explosive charge.

scholarly journals Optimal Design of Multi-Span Pitched Roof Frames with Tapered Members

2018 ◽  
Author(s):  
Ali Kaveh ◽  
Mohammad Zaman Kabir ◽  
Mahdi Bohlool
Keyword(s):  
Optimal Design ◽  
Heuristic Algorithms ◽  
Optimization Algorithms ◽  
Lateral Loads ◽  
Optimal Weight ◽  
Industrial Buildings ◽  
Optimum Weight ◽  
Apex Height ◽  
Tapered Members

Many industrial buildings require large spans and high height, and the use of a frame with inclined roofs with non-prismatic elements can reduce the usage of steel. Pitched roof frame with single spans are optimized using different meta-heuristic algorithms. In this paper, the optimal design of industrial frames with two and three spans under gravity and lateral loads is performed. Five efficient and widely accepted optimization algorithms are used to optimize each frame. The convergence histories and design results of these algorithms are compared and the most suitable algorithm is determined. In each frame, the effect of increasing the apex height is evaluated on the optimal weight and the best angle is determined for optimum weight.

Flatness-Based Open Loop Command Tracking for Quasistatic Microscanners

2013 ◽  
Author(s):  
Klaus Janschek ◽  
Richard Schroedter ◽  
Thilo Sandner
Keyword(s):  
Laser Scanning ◽  
Open Loop ◽  
Model Parameters ◽  
Trajectory Design ◽  
Ansys Analysis ◽  
Out Of Plane ◽  
Mechanical Suspension ◽  
Mass Spring ◽  
Performance Results ◽  
Nonlinear Elastic

This paper describes a nonlinear command tracking scheme for an electrostatic laser scanning micromirror assembly. The results are based on an innovative gimballed comb transducer concept developed at the Fraunhofer Institute for Photonic Microsystems. The outer mirror axis is designed as a Staggered Vertical Comb (SVC) in out-of-plane configuration and it shall provide a quasistatic operation with large deflection angles for triangular trajectories. The challenges for trajectory design and open loop command tracking are determined by the inherently nonlinear transducer characteristics and the lightly damped mass-spring dynamics. In this paper a flatness-based trajectory design is presented that considers the nonlinear transducer dynamics as well as the nonlinear elastic mechanical suspension with model parameters derived from ANSYS analysis. The paper discusses design constraints and detailed design considerations and it shows proof of concept performance results based on experimental verification with a real microscanner assembly.

scholarly journals Performance of Outrigger System by Non-Linear Static Method

2019 ◽  
Vol 8 (12) ◽  
pp. 4128-4132
Keyword(s):  
Lateral Force ◽  
Optimum Level ◽  
Building Structures ◽  
Lateral Loads ◽  
Reinforced Concrete Structure ◽  
Concrete Walls ◽  
Building Models ◽  
Non Linear ◽  
Pushover Curve ◽  
Outer Perimeter

High rise building structures are highly affected by lateral loads and wind forces. To enhance lateral force outrigger systems are developed, which are one of the most popular and efficient, because they are easier to build and they provides good lateral stiffness. With the rise of building height, deep beam become concrete walls at least of one story height. Axial shortening effect between core and perimeter structure has to be considered.In the present work 20 story reinforced concrete structure has taken with outrigger walls attached from core to the outer perimeter column. By changing the different position of outrigger level are kept for analysis.The building without and with outrigger are compared with bareframe. These are different building models analysed (a) Bare frame of twenty story building (b) Bare frame with core shear wall building (c) Outrigger system at top of building (d) Outrigger system at top & 0.75 Height of building (e) Outrigger system at top & 0.50 Height of building (f) Outrigger system at top & 0.25 Height of building. Non-linear static analysis results were compared. The analytical methods used in the work are pushover method. In this work, various parameters like pushover curve, displacement vs base force, story displacement, hinges formation are obtained for all the models.Outrigger at optimum level at 0.5 Height gives better results in both displacements and base force. To sustain peak lateral loads these systems are provided half of the height. These study gives has inelastic behaviour of structure.

Static and Dynamic Analysis of Multi-Story Buildings, Including P-Delta Effects

1987 ◽  
Vol 3 (2) ◽  
pp. 289-298 ◽  
Author(s):  
E. L. Wilson ◽  
A. Habibullah
Keyword(s):  
Dynamic Analysis ◽  
Stiffness Matrix ◽  
Mode Shapes ◽  
Building Structures ◽  
Structural Stiffness ◽  
Lateral Loads ◽  
Static And Dynamic Analysis ◽  
Geometric Stiffness ◽  
Area Of Concern ◽  
Structural Engineers

The P-Delta phenomenon is an area of concern to structural engineers. Traditional methods for incorporating P-Delta effects in analysis are based on iterative techniques. These techniques are time-consuming and are in general used for static analysis only. For building structures, the mass, which causes the P-Delta effect, is constant irrespective of the lateral loads and displacements. This information is used to linearize the P-Delta effect for buildings and solve the problem “exactly”, satisfying equilibrium in the deformed position, without iterations. An algorithm is developed that incorporates the P-Delta effects into the basic formulation of the structural stiffness matrix as a geometric stiffness correction. This procedure can be used for both static and dynamic analysis and will account for the lengthening of the structural time periods and changes in mode shapes due to P-Delta effects. The algorithm can be directly incorporated into building analysis programs.

Full-Scale Measurements on Vibrations of a 51-Story Tall Building Due to a Major Earthquake and Typhoon

2013 ◽  
Vol 284-287 ◽  
pp. 1259-1263 ◽  
Author(s):  
Kun Sung Liu ◽  
Yi Ben Tsai
Keyword(s):  
Transfer Functions ◽  
Tall Building ◽  
Building Structures ◽  
Ambient Vibrations ◽  
Structural Dynamic ◽  
High Rise ◽  
Taipei City ◽  
Structural Dynamic Characteristics ◽  
Strong Winds ◽  
Northern Taiwan

The Shin Kong Tower located in Taipei City has a height of 244.15 m. It was the tallest building in northern Taiwan when it was built in 1993. This super tall building is susceptible to severe vibrations induced by strong winds or earthquakes. Safety of the building structures and its contents as well as the comfort of its occupants under such strong forces remains a significant engineering concern. Records by a structural array in the 51-story SK Building of the 1999 M7.6 Chi-Chi earthquake and 2004 Typhoon Aere are analyzed in this study. As a result, the structural dynamic characteristics of the high-rise building, including the transfer functions and natural frequencies, excited by the Chi-Chi earthquake, Typhoon Aere, and ambient vibrations are also determined and compared.

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