scholarly journals Seismic Design of Steel Moment-Resisting Frames with Damping Systems in Accordance with KBC 2016

2019 ◽  
Vol 9 (11) ◽  
pp. 2317
Author(s):  
Seong-Ha JEON ◽  
Ji-Hun PARK ◽  
Tae-Woong HA
Keyword(s):  
Nonlinear Response ◽  
Damping Ratio ◽  
Design Procedure ◽  
Period Change ◽  
Reduction Factor ◽  
Design Parameters ◽  
Efficient Design ◽  
Moment Frames ◽  
Seismic Force ◽  
Damping Systems

An efficient design procedure for building structures with damping systems is proposed using nonlinear response history analysis permitted in the revised Korean building code, KBC 2016. The goal of the proposed procedure is to design structures with damping systems complying with design requirements of KBC 2016 that do not specify a detailed design method. The proposed design procedure utilizes response reduction factor obtained by a limited number of nonlinear response history analyses of the seismic-force-resisting system with incremental damping ratio substituting damping devices. Design parameters of damping device are determined taking into account structural period change due to stiffness added by damping devices. Two design examples for three-story and six-story steel moment frames with metallic yielding dampers and viscoelastic dampers, respectively, shows that the proposed design procedure can produce design results complying with KBC 2016 without time-consuming iterative computation, predict seismic response accurately, and save structural material effectively.

An Evaluation of Two-Level Seismic Design Procedure

1993 ◽  
Vol 9 (1) ◽  
pp. 121-135 ◽  
Author(s):  
Chia-Ming Uang
Keyword(s):  
Structural Damage ◽  
Limit State ◽  
Design Procedure ◽  
Reduction Factor ◽  
Performance Criteria ◽  
Ultimate Limit State ◽  
Seismic Codes ◽  
Seismic Force ◽  
Force Reduction Factor ◽  
Force Reduction

The two-level design philosophy is recognized by modern seismic codes. When this philosophy is implemented in the code, the intensities of the two design earthquakes, the structural performance criteria, explicit versus implicit design approach, and the effectiveness to achieve the performance criteria vary considerably from one code to the other. For the ultimate limit state, the UBC was compared with seismic codes of Canada, Japan, and Eurocode. It was found that a trend to deviate from the UBC approach of using a single seismic force reduction factor (i.e., Rw) is apparent. Instead, an approach using a compound force reduction factor which considers the contribution of structural ductility and structural overstrength is preferred. For the serviceability limit state, a comparison of the level of design earthquakes and performance criteria of the UBC, Tri-Services Manual, and the Japanese code indicates that the UBC produces the most flexible structure, and that UBC does not control structural damage. It is suggested that the UBC adopts an explicit serviceability design procedure.

An Efficient Design Procedure for MEMS Electrothermal Microgripper

2021 ◽  
pp. 1-6
Author(s):  
Ananya Roy ◽  
Rajasree Sarkar ◽  
Arunava Banerjee ◽  
M Nabi
Keyword(s):  
Design Parameter ◽  
Low Voltage ◽  
Design Procedure ◽  
Design Parameters ◽  
Optimized Design ◽  
Efficient Design ◽  
The Finite Element Method ◽  
Compact Size ◽  
Sine Cosine Algorithm ◽  
Parameter Values

Abstract With the development of miniaturization technology, MEMS electrothermal microgrippers have been widely used owing to their compact size, ease of manufacturing, and low production cost. Since most of these systems are governed by partial differential equations (PDEs), modeling of microgrippers poses a significant challenge for designers. To reduce the overall computational complexity, it is a common practice to model the microgripper system using the finite element method (FEM). During the design process, the geometric and analytical properties of the microgripper influence the system dynamics to a great extent, and this work focuses on studying the effects of such parameter changes. In low voltage applications, the performance of the microgripper is influenced by the geometrical variations, and the air gap. Hence, for the modeling of the microgripper, actuator arm lengths, and the gap between the arms are chosen as the two main geometric design parameters, while the input current density is considered as the analytical design parameter. In this work, the optimized design parameter values for maximum possible displacement are obtained with the use of Sine Cosine Algorithm (SCA). Further, an averaging operation is proposed for efficiently designing the MEMS electrothermal microgripper, and the efficacy of the proposed design methodology is demonstrated through simulation studies.

Design Approach To Bolted End-Plate Vertical-Slits RWS Connection

2021 ◽  
Author(s):  
Hamidreza Nazaralizadeh ◽  
Hamid Ronagh ◽  
Parham Memarzadeh ◽  
Farhad Behnamfar
Keyword(s):  
Numerical Models ◽  
Design Procedure ◽  
Cost Effective ◽  
Design Parameters ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Reduced Beam Section ◽  
End Plate ◽  
Beam Section ◽  
Rbs Connections

Abstract Extensive research has been carried out on steel moment frames to improve the cyclic performance of seismic resisting connections with reduced beam section (RBS). The RBS connections are conventionally known by the radial reduction of the beam flange. Where the contribution of the beam flange to the flexural resistance is greater than that of the beam web, some researchers have proposed reduced web section (RWS) connections, instead. The present study dedicates to the RWS connections with vertical-slits (VS), as a cost-effective alternative with multiple design parameters. This paper aims to obtain proper ranges for the geometric design parameters of the VS-RWS connection. In this order, two full-scale specimens of the bolted end-plate VS-RWS connection were experimentally tested under the SAC cyclic loading to evaluate the performance of connections, and then a parametric study was carried out using the verified numerical models. The parameters consist of the distance between the column face and the beginning of the reduced region, the length of the reduced region, as well as the depth and width of the vertical-slits. Based on the results, certain recommendations for the ranges of the geometric parameters of VS-RWS have been suggested. In order to obtain the story drift of the frame caused by the VS-RWS beam flexural deformation using the conjugate beam method, the original VS-RWS was replaced with an equivalent constant-cut reduced beam section (CC-RBS). At last, a simple design procedure for VS-RWS connections was provided according to AISC-358.

Direct Displacement-Based Seismic Design of Propped Rocking Walls

2015 ◽  
Vol 31 (1) ◽  
pp. 179-196 ◽  
Author(s):  
Afsoon Nicknam ◽  
Andre Filiatrault
Keyword(s):  
Nonlinear Response ◽  
Design Procedure ◽  
Seismic Intensity ◽  
Ground Shaking ◽  
Direct Displacement Based Design ◽  
Seismic Force ◽  
Supplemental Damping ◽  
Displacement Based ◽  
Rocking Walls ◽  
Strong Ground

A direct displacement-based design (DDBD) methodology is described for propped rocking walls (PRWs). PRWs represent a novel seismic force-resisting system that combines passive supplemental damping devices with unbonded post-tensioned concrete rocking walls. The key aspect of the proposed design procedure is the closed-form derivation of the stabilized hysteretic response of PRWs under reverse cyclic loading. This allows the direct application of the DDBD procedure to satisfy desired displacement performance objectives under prescribed levels of seismic intensity. Nonlinear response analyses are conducted on a prototype PRW structure, designed according to the proposed DDBD procedure to evaluate its performance under strong ground shaking.

Robustness Evaluation of Mapping Techniques for Automated Servo Robot Design

2006 ◽  
Author(s):  
Michael R. Hansen ◽  
Torben O. Andersen
Keyword(s):  
Design Procedure ◽  
Planetary Gear ◽  
Performance Criteria ◽  
Design Parameters ◽  
Efficient Design ◽  
Computationally Efficient ◽  
Data Bases ◽  
Open Chain ◽  
Dimensionless Parameters ◽  
Working Cycle

Work has been carried out to investigate some of the important design parameters and performance criteria that should be addressed when designing servo mechanisms and, subsequently, to put forward a computationally efficient design procedure. Emphasis is put on the handling of the discrete design variables. A two-stage approach is presented that uses dimensionless parameters that maps data bases of commecially available components. At the first stage the dimensionless parameter are allowed to assume any value. At the second stage the dimensionless parameters are pushed towards integer values by means of penalization techniques. A three-degree of freedom open chain spatial mechanism is used as the fixed mechanism topology of the study. Each drive consists of an inverter driven servo motor attached to a planetary gear. In the optimization the design are evaluated based on a typical working cycle involving the positioning of a certain payload. The design criteria include costs of drives and structural components, tool point precision, fatigue in welded details, over heating and stalling of the motors and gears as well as time of operation. The work is a continuation of previous work and emphasis in this paper is on the robustness of the method and the organization of the data bases.

scholarly journals Rationality Analysis of High-rise Building Structure Calculation un- der SATWE Procedure

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Fan Guiqing
Keyword(s):  
Structural Design ◽  
Structural Model ◽  
Design Procedure ◽  
Design Parameters ◽  
Land Resources ◽  
High Rise ◽  
Structural Problems ◽  
Seismic Force ◽  
Structural Calculation ◽  
Capital Construction

In recent years, with the increasing shortage of land resources in our country, in or der to make full use of limited land resources, the development of construction industry is developing towards high-rise and super-high-rise buildings.This is based on the use of structural design and structural calculation of building structures with the higher requirement. For structural designers, the structural model is determined reasonably, the structural design procedure is used correctly, the design parameters and seismic force parameters are accurately input, the results are correctly analyzed and the structural calculation model is adjusted according to the calcu- lated results. Repeated adjustments in order to design safe high-rise buildings, so that the capital construction investmenthas been rationally used. In this paper, how to use the SATWE program developed by China Academy of Building Science to study the structural calculation and structural problems, how to analyze the calculation results and use the calculated results to reflect the problem and then adjust the structural model and other issues to study.

Error-aware Design Procedure to Implement Energy-efficient Approximate Squaring Hardware

2020 ◽  
Vol 10 (4) ◽  
pp. 471-477
Author(s):  
Merin Loukrakpam ◽  
Ch. Lison Singh ◽  
Madhuchhanda Choudhury
Keyword(s):  
Energy Saving ◽  
Relative Error ◽  
Energy Efficient ◽  
Piecewise Linear ◽  
Arithmetic Operation ◽  
Design Procedure ◽  
Digital Signal ◽  
Maximum Relative Error ◽  
Square Function ◽  
Efficient Design

Background:: In recent years, there has been a high demand for executing digital signal processing and machine learning applications on energy-constrained devices. Squaring is a vital arithmetic operation used in such applications. Hence, improving the energy efficiency of squaring is crucial. Objective:: In this paper, a novel approximation method based on piecewise linear segmentation of the square function is proposed. Methods: Two-segment, four-segment and eight-segment accurate and energy-efficient 32-bit approximate designs for squaring were implemented using this method. The proposed 2-segment approximate squaring hardware showed 12.5% maximum relative error and delivered up to 55.6% energy saving when compared with state-of-the-art approximate multipliers used for squaring. Results: The proposed 4-segment hardware achieved a maximum relative error of 3.13% with up to 46.5% energy saving. Conclusion:: The proposed 8-segment design emerged as the most accurate squaring hardware with a maximum relative error of 0.78%. The comparison also revealed that the 8-segment design is the most efficient design in terms of error-area-delay-power product.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Optimal Design of Vibration Absorber Systems Supported by Elastic Base

1991 ◽  
Author(s):  
Hashem Ashrafiuon
Keyword(s):  
Dynamic Models ◽  
Damping Ratio ◽  
Equations Of Motion ◽  
Elastic Base ◽  
Design Parameters ◽  
Primary System ◽  
Vibration Absorbers ◽  
Equivalent Damping ◽  
System Equations ◽  
Different Levels

Abstract This paper presents the effect of foundation flexibility on the optimum design of vibration absorbers. Flexibility of the base is incorporated into the absorber system equations of motion through an equivalent damping ratio and stiffness value in the direction of motion at the connection point. The optimum values of the uncoupled natural frequency and damping ratio of the absorber are determined over a range of excitation frequencies and the primary system damping ratio. The design parameters are computed and compared for the rigid, static, and dynamic models of the base as well as different levels of base flexibility.

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