Multistable Cosine-Curved Dome System for Elastic Energy Dissipation

2019 ◽  
Vol 86 (9) ◽  
Author(s):  
Mansour Alturki ◽  
Rigoberto Burgueño
Keyword(s):  
Energy Dissipation ◽  
Analytical Model ◽  
Nonlinear Behavior ◽  
Experimental Tests ◽  
High Energy ◽  
Bistable System ◽  
Dissipated Energy ◽  
Element Analysis ◽  
The Individual ◽  
Hysteretic Response

This paper presents a new energy dissipation system composed of multistable cosine-curved domes (CCD) connected in series. The system exhibits multiple consecutive snap-through and snap-back buckling behavior with a hysteretic response. The response of the CCDs is within the elastic regime and hence the system's original configuration is fully recoverable. Numerical studies and experimental tests were conducted on the geometric properties of the individual CCD units and their number in the system to examine the force–displacement and energy dissipation characteristics. Finite element analysis (FEA) was performed to simulate the response of the system to develop a multilinear analytical model for the hysteretic response that considers the nonlinear behavior of the system. The model was used to study the energy dissipation characteristics of the system. Experimental tests on 3D printed specimens were conducted to analyze the system and validate numerical results. Results show that the energy dissipation mainly depends on the number and the apex height-to-thickness ratio of the CCD units. The developed multilinear analytical model yields conservative yet accurate values for the dissipated energy of the system. The proposed system offered reliable high energy dissipation with a maximum loss factor value of 0.14 for a monostable (self-recoverable) system and higher for a bistable system.

Stiffness, Ductility, and Energy Dissipation of RC Elements under Cyclic Shear

2005 ◽  
Vol 21 (4) ◽  
pp. 1093-1112 ◽  
Author(s):  
Thomas T. C. Hsu ◽  
Mohamad Y. Mansour
Keyword(s):  
Energy Dissipation ◽  
High Energy ◽  
Shear Stresses ◽  
Principal Stresses ◽  
Element Analysis ◽  
Rc Structures ◽  
Cyclic Shear ◽  
Steel Bar ◽  
High Energy Dissipation ◽  
Reversed Cyclic

A new Cyclic Softened Membrane Model (CSMM) was recently developed to predict the stiffness, ductility, and energy dissipation of reinforced concrete (RC) elements subjected to reversed cyclic shear. Using the nonlinear finite element analysis, we can integrate these responses of elements to predict the behavior of a whole structure, such as a low-rise shear wall, subjected to earthquake action. This study of CSMM summarizes systematically the effects of the two primary variables: the steel bar angle with respect to the direction of the applied principal stresses and the steel percentage. The results clearly show that RC structures under cyclic shear stresses could be designed to be very ductile, have large stiffness, and possess high energy-dissipation capacities (just like flexural-dominated elements), if the steel bars are properly oriented in the directions of principal stresses and if the steel percentages are kept within certain limits.

Combined stiffness characteristic of metal rubber material under vibration loads

2019 ◽  
Vol 233 (17) ◽  
pp. 6076-6088 ◽  
Author(s):  
Hailong Fu ◽  
Zhengli Hua ◽  
Longqing Zou ◽  
Yue Wang ◽  
Jianbin Ye
Keyword(s):  
Energy Dissipation ◽  
Vibration Isolation ◽  
Influence Factors ◽  
Experimental Tests ◽  
Individual Element ◽  
Rubber Material ◽  
Static Tests ◽  
Metal Rubber ◽  
Vibration Loads ◽  
The Individual

Metal rubber is one kind of elastic cellular metal material, which is widely used in vibration isolation environment for its excellent properties of elasticity, energy dissipation, and environmental adaptability. However, the stiffness range of one single metal rubber is restricted, which limits its ability of vibration isolation, especially under the complex vibration loads. In this paper, a method of spatial overlay combination is presented to widen the range of the stiffness of metal rubber material. The contact behavior of the metal spiral rolls and the influence factors of manufacture to the stiffness are investigated according to the micro-spring theory and the energy dissipation theory. The static tests under cycling loading are conducted to obtain the average stiffness and the equivalent stiffness of the combined metal rubber. After the comparisons, the combined metal rubber has a better stiffness range than the individual element. The diameter of metal wire and the relative density of metal rubber are two important influence factors to the combined stiffness, which are verified by the experimental tests and finite element simulation.

Analytical Modelling of Elastic Interaction in Bolted Flange Gasketed Joints

2017 ◽  
Author(s):  
Linbo Zhu ◽  
Abdel-Hakim Bouzid ◽  
Jun Hong
Keyword(s):  
Analytical Model ◽  
Nuclear Power ◽  
Power Plants ◽  
Experimental Tests ◽  
Elastic Interaction ◽  
Industrial Complex ◽  
Element Analysis ◽  
Minimum Number ◽  
Leakage Failure ◽  
Bolted Flange

Bolted flange joints are widely used in the fossil and nuclear power plants and other industrial complex. During their assembly, it is extremely difficult to achieve the target bolt preload and tightening uniformity due to elastic interaction. In addition to the severe service loadings the initial bolt load scatter increases the risk of leakage failure. The objective of this paper is to present an analytical model to predict the bolt tension change due to elastic interaction during the sequence of initial tightening. The proposed analytical model is based on the theory of circular beams on linear elastic foundation. The elastic compliances of the flanges, the bolts, and the gasket due to bending, twisting and axial compression are involved in the elastic interaction. The developed model can be used to optimize the initial bolt load tightening to obtain a uniform final preload under minimum number of tightening passes. The approach is validated using finite element analysis and experimental tests conducted on a NPS 4 class 900 weld neck bolted flange joint.

scholarly journals The stress ratio effect on plastic dissipation during fatigue crack growth

2018 ◽  
Vol 165 ◽  
pp. 13002
Author(s):  
H. Quan ◽  
R.C. Alderliesten ◽  
R. Benedictus
Keyword(s):  
Fatigue Crack ◽  
Energy Dissipation ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stress Ratio ◽  
Dissipated Energy ◽  
Plastic Energy ◽  
Plastic Dissipation ◽  
Stress Ratios ◽  
The Individual

Plastic energy dissipation is inevitable during fatigue crack growth. There have been previous attempts reported in literature to correlate the plastic dissipated energy (dW/dN) to fatigue crack growth rate (da/dN). However, at a given dW/dN, the da/dN changes with the ratio of minimum and maximum loads, known as the stress ratio. This paper describes an experimental study carried out on 2024-T3 central crack tension specimens to quantify the relation between dW/dN and da/dN. By selecting different stress ratios in the individual tests, the experiments reveal the influence of the stress ratio on this relationship. It is evident that dW/dN has no unique relationship with da/dN valid for the tested stress ratios. Instead, the relationship for each stress ratio is different. This is illustrated with the value of plastic dissipation per unit of fatigue crack growth (dW/da), representing the effective resistance to the crack increment. This value is not a constant, but changes with the stress ratios and da/dN values. Hence the plastic energy dissipation cannot be used directly for predicting crack growth.

Gaussian Specimens for Gigacycle Fatigue Tests: Evaluation of Temperature Increment

2014 ◽  
Vol 627 ◽  
pp. 85-88 ◽  
Author(s):  
A. Tridello ◽  
D.S. Paolino ◽  
G. Chiandussi ◽  
Massimo Rossetto
Keyword(s):  
Size Effect ◽  
Analytical Model ◽  
Experimental Tests ◽  
Fatigue Tests ◽  
Mechanical Power ◽  
Testing Time ◽  
Element Analysis ◽  
Temperature Increment ◽  
Material Volume ◽  
Volume Size

Experimental tests investigating very-high-cycle fatigue (VHCF) properties of materials are commonly performed with ultrasonic testing machines, which allow for a significant reduction of testing time. In order to evaluate the effect of tested material volume (size-effect) on VHCF properties, the Authors recently proposed to adopt Gaussian specimens for VHCF tests. Investigation of size-effect with Gaussian specimen induces large mechanical power dissipation and temperature increment that must be taken into account. The present paper proposes an analytical model, which allows to approximately predict the dissipated mechanical power and the temperature increment in Gaussian specimens. The analytical model is also numerically verified through a Finite Element Analysis.

Load Transfer in a Space Frame Connection

1992 ◽  
Vol 7 (3) ◽  
pp. 191-200 ◽  
Author(s):  
Erling Murtha-Smith ◽  
Sun-Hee Hwang ◽  
John E. Bean
Keyword(s):  
Load Transfer ◽  
Experimental Tests ◽  
Shear Mode ◽  
Space Frame ◽  
Element Analysis ◽  
Good Correspondence ◽  
Load Paths ◽  
The Individual ◽  
System 1 ◽  
Good Agreement

The connection of the Unistrut “System 1” double layer grid space frame transfers loads statically indeterminately from a member to the connection plate through two lugs and a bolt. The connection is studied by Finite Element analysis, design code analysis and a series of experimental tests. There is quite good agreement between the analysis methods and fair agreement with the tests. The test series isolates the contributions of the individual load paths showing quite good correspondence. The failure of the lugs in an unpredicted shear mode is the major cause for discrepancies. However, analysis of that shear mode is consistent with the tests.

Finite Element Analysis of Composite Replaceable Short Links

2018 ◽  
Vol 763 ◽  
pp. 576-583
Author(s):  
Mariana Zimbru ◽  
Mario D'Aniello ◽  
Aurel Stratan ◽  
Raffaele Landolfo ◽  
Dan Dubină
Keyword(s):  
Finite Element ◽  
Experimental Tests ◽  
High Energy ◽  
Braced Frames ◽  
Ultimate Shear Strength ◽  
Element Analysis ◽  
Eccentrically Braced Frames ◽  
Tensile Forces ◽  
Shear Distortion ◽  
High Energy Dissipation

Eccentrically braced frames (EBF) with detachable short links are an efficient solution for buildings in seismic areas owing to their high energy dissipation capacity and ductility and ease of repair in the earthquake aftermath. Past studies revealed that short links can develop shear overstrength (i.e. Vu/Vp, where Vu is the ultimate shear strength and Vp the corresponding plastic resistance) larger than the value recommended in EC8 [1] (i.e. Vu/Vp =1.5). One of the factors causing the higher shear overstrength is the presence of axial restraints that leads to the development of tensile forces in the link at large levels of rotation. Another reason for higher shear overstrength is the composite slab that can resist the shear distortion together with the short link. Within the DUAREM project [2], full scale pseudo-dynamic experimental tests were carried out on 3D EBF allowing thus the investigation of replaceable links considering two arrangements: (i) steel solution – the link was uncoupled from the slab (ii) composite solution – the slab and link are connected. The aim of this paper is to present the results of finite element analyses (FEAs), based on calibrated models and the comparison between the obtained results and the experimental tests performed by [2]. The numerical investigation carried out aims to evaluate the shear overstrength and the level of axial force in the link for both tested configurations.

Evaluation of a low-cost seismic energy dissipation device for buildings

2021 ◽  
Author(s):  
Héctor Guerrero ◽  
Roberto Gomez ◽  
J. Alberto Escobar
Keyword(s):  
Energy Dissipation ◽  
Low Cost ◽  
Structural Response ◽  
Seismic Energy ◽  
Seismic Loading ◽  
Experimental Tests ◽  
Dissipated Energy ◽  
High Tech ◽  
Human Right ◽  
Existing Structures

<p>Safety during earthquakes should be a human right and shall be accessible not only to those who can pay for proprietary high-tech devices but to everyone. Based on that, this paper presents a low- cost, low-tech seismic energy dissipation device. Its experimental behaviour under seismic loading is assessed. The device is classified as buckling-restrained brace (BRB) and, according to its characteristics, it is suitable for new and existing, medium- to low-rise structures. First, the device composing parts are presented. Then, its structural response, in terms of hysteretic behaviour, ductility, and dissipated energy – as obtained from experimental tests – is shown. Experimental results show an excellent behaviour. As a result, it can be said that the device is reliable and its use is recommended for new and existing structures. Design recommendations are also provided.</p>

scholarly journals Analytical Model of Bolted Joint Structure and Its Nonlinear Dynamic Characteristics in Transient Excitation

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Xin Liao ◽  
Jianrun Zhang ◽  
Xiyan Xu
Keyword(s):  
Dynamic Response ◽  
Analytical Model ◽  
Nonlinear Behavior ◽  
Nonlinear Effects ◽  
Tangential Direction ◽  
Nonlinear Stiffness ◽  
Bolted Joint ◽  
Element Analysis ◽  
Simulation Results ◽  
Cubic Stiffness

The dynamic response of crucial components often depends upon the dynamic behavior of bolted connections. As is usually the case, the accurate modeling of structures with many mechanical joints remains a challenge work. The nonlinear behavior included in assembled structures strongly depends on the interface properties. In this paper, an analytical model of the simple bolted joint beam in tangential direction is first proposed for transient excitation, based on phenomenological model. The fourth-order Runge-Kutta method is employed to calculate the transient response, where the dynamic response of the nonlinear stiffness on system is also investigated. The simulation results show that natural frequency has a certain dependence on cubic stiffness term and cubic stiffness is more suitable for modeling of nonlinear system of a wider frequency range. Thereby, a series Iwan model containing cubic stiffness term is established to describe nonlinear behaviors of bolted joint beams in shear vibration. The amplitude-frequency curves show that the influence of interaction between nonlinear stiffness and damping mechanism on dynamic response characteristics is more obvious. Finally, a new type of nonlinear model is applied into finite element analysis. The results of proposed transient excitation experiment are discussed qualitatively, indicating that nonlinear effects observed agree with the numerical simulation results.

scholarly journals EXPERIMENTAL BEHAVIOUR OF A LOW-COST SEISMIC ENERGY DISSIPATION DEVICE

2020 ◽  
pp. 65-81
Author(s):  
Héctor Guerrero Bobadilla ◽  
Emmanuel Zamora Romero ◽  
Jose Alberto Escobar Sánchez ◽  
Roberto Gómez Martínez
Keyword(s):  
Energy Dissipation ◽  
Low Cost ◽  
Structural Response ◽  
Seismic Energy ◽  
Experimental Tests ◽  
Hysteretic Behavior ◽  
Dissipated Energy ◽  
High Tech ◽  
Seismic Safety ◽  
Existing Structures

Safety during earthquakes should be a human right and shall be accessible not only to those who can pay for proprietary high-tech devices but to everyone. Based on that, this study has been developed with the intention of helping to improve the seismic safety in the developing world. Within this paper, a low-cost, low-tech seismic energy dissipation device is proposed. Its experimental behavior under seismic loading is assessed. The device type is buckling-restrained brace (BRB) and, according to its characteristics, it is suitable for new and existing, medium- to low-rise structures. First, the device characteristics and fabrication process are presented. Then, its structural response, in terms of the hysteretic behavior, ductility, and dissipated energy – as obtained from experimental tests – is shown. Experimental results show an excellent behavior of the proposed device. As a result, it can be said that the device is reliable and its use is recommended for new, and retrofitting/upgrading existing, structures. Design recommendations are also provided.

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