Design of porous and graded NiTi smart energy absorbers considering synthetic uncertainty in parameters

2020 ◽  
pp. 1045389X2097790
Author(s):  
Sourav Gur ◽  
George N Frantziskonis
Keyword(s):  
Energy Dissipation ◽  
Optimal Design ◽  
Shape Factor ◽  
Robust Design Optimization ◽  
Nominal Stress ◽  
Design Parameters ◽  
Niti Shape Memory Alloy ◽  
Critical Design ◽  
Extreme Response ◽  
Energy Dissipation Capacity

The synthetic uncertainty (SU) method is introduced and applied to the optimal design of energy absorbing NiTi shape memory alloy (SMA) bars. A sensitivity analysis for a large number of stochastic parameters identifies geometrical grading, porosity, and imposed maximum nominal stress as critical design parameters for the energy dissipation capacity of the bars. Parametric uncertainty on the optimal design of the energy absorber is incorporated and estimated through the SU formalism. The SU method provides a unified approach to discover the critical design parameters, quantify uncertainty, and optimally design a system around its extreme response (maximum or minimum). Therefore, the SU method is placed next to the robust design optimization (RDO) process, yet with a discovery component. It is found that variations in porosity and shape factor can significantly alter the stress-strain response and energy dissipation capacity. For a given value of maximum nominal stress, it is found that there exists an optimal combination of shape factor and porosity which maximizes the energy dissipation capacity of a tapered and porous NiTi bar.

Estimation of Seismic Energy Dissipation for Steel Slit Shear Walls Considering Out-of-Plane Buckling

2021 ◽  
Author(s):  
Yiming Ma ◽  
Liusheng He ◽  
Ming Li
Keyword(s):  
Energy Dissipation ◽  
Shear Walls ◽  
Seismic Energy ◽  
Thickness Ratio ◽  
Design Parameters ◽  
Test Results ◽  
Loading Test ◽  
Aspect Ratios ◽  
Out Of Plane ◽  
Energy Dissipation Capacity

Steel slit shear walls (SSSWs), made by cutting slits in steel plates, are increasingly adopted in seismic design of buildings for energy dissipation. This paper estimates the seismic energy dissipation capacity of SSSWs considering out-of-plane buckling. In the experimental study, three SSSW specimens were designed with different width-thickness ratios and aspect ratios and tested under quasi-static cyclic loading. Test results showed that the width-thickness ratio of the links dominated the occurrence of out-of-plane buckling, which produced pinching in the hysteresis and thus reduced the energy dissipation capacity. Out-of-plane buckling occurred earlier for the links with a larger width-thickness ratio, and vice versa. Refined finite element model was built for the SSSW specimens, and validated by the test results. The concept of average pinching parameter was proposed to quantify the degree of pinching in the hysteresis. Through the parametric analysis, an equation was derived to estimate the average pinching parameter of the SSSWs with different design parameters. A new method for estimating the energy dissipation of the SSSWs considering out-of-plane buckling was proposed, by which the predicted energy dissipation agreed well with the test results.

Experimental Test of Welded Wide Flange Fuses

2018 ◽  
Vol 763 ◽  
pp. 414-422 ◽  
Author(s):  
Tony Y. Yang ◽  
Winda Banjuradja ◽  
Lisa Tobber
Keyword(s):  
Energy Dissipation ◽  
Longitudinal Direction ◽  
Elastic Stiffness ◽  
Design Parameters ◽  
Structural Components ◽  
Earthquake Energy ◽  
Aspect Ratios ◽  
Metallic Dampers ◽  
Energy Dissipation Capacity ◽  
Metallic Damper

Metallic dampers are one of the most prevalent structural components that are used to dissipate earthquake energy. A novel metallic damper, named Welded Wide Flange Fuse (WWFF), is proposed in this paper. WWFF utilizes commonly available welded wide flange sections to dissipate the earthquake energy through shear yielding of the web in the longitudinal direction, which makes the WWFF easy to be fabricated and efficient in providing high elastic stiffness and stable energy dissipation capacity. In this paper, a detailed experimental study was conducted to examine the influence on the design parameters (such as aspect ratios and slenderness ratios) on the component response (such as yielding force and elastic stiffness). The result shows that the WWFF has stable energy dissipation capacity which can be used as an efficient and robust metallic damper.

ENERGY DISSIPATION IN POST-TENSIONED SELF-CENTERING PRECAST CONCRETE CONNECTIONS WITH A FRICTION DEVICE

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Takeaki Koshikawa
Keyword(s):  
Energy Dissipation ◽  
Friction Force ◽  
Precast Concrete ◽  
Design Parameters ◽  
Effective Energy ◽  
Energy Dissipation Capacity ◽  
Post Tensioning ◽  
The Moment ◽  
The Relationship ◽  
Post Tensioned

This paper presents an analytical study on the energy dissipation capacity of unbonded post-tensioned self-centering precast concrete beam-column connections that have a friction device only below the beam or on the web. The energy dissipation capacity is quantified using an effective energy dissipation ratio. To quantitatively evaluate the influence of three design parameters on the energy dissipation capacity, nonlinear analyses were carried out using a section-analysis method to predict the relationship between the moment and the relative rotation at the beam-column interface under cyclic loading. The design parameters were the initial post-tensioning force in the unbonded post-tensioning tendon, the friction force, and the location of the friction device. The analysis results show that the effective energy dissipation ratios for connections whose friction devices are in the same location can be related to the ratio of the friction force to the initial post-tensioning force.

Damage Sensitivity Analysis for Main Design Parameters of Reinforced Concrete Shear Wall

2011 ◽  
Vol 374-377 ◽  
pp. 2574-2577
Author(s):  
Shan Suo Zheng ◽  
Qing Lin Tao ◽  
Yi Hu ◽  
Zhi Qiang Li
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Seismic Wave ◽  
Wave Energy ◽  
Shear Wall ◽  
Hybrid Structure ◽  
Design Parameters ◽  
Main Design ◽  
Energy Dissipation Capacity ◽  
Rc Shear Wall

As an indispensable force component to the hybrid structure, the seismic wave energy inputted into integral structure is dissipated by damping force working and plastic hysteresis of reinforced concrete shear wall which is taken as the first seismic fortification line of structure. Considering of the condition that the RC shear wall is mainly used to dissipate the seismic wave energy, this paper takes the ultimate energy dissipation capacity of reinforced concrete shear wall subjected to cyclic loading as the damage characterization. According to the related theoretical analysis and experimental research, the method for calculating ultimate energy dissipation capacity of RC shear wall is proposed and the damage sensitivity of various design parameters which contain the sectional thickness, the strength of concrete and reinforcement ratio are analyzed, then the influence laws of main design parameters impacted on damage evolution of RC shear wall are revealed in this paper. The research shows that sectional thickness is the most sensitive factor in the damage of reinforced concrete shear wall and the concrete strength degree takes the second place, and then the reinforcement ratio is the most insensitive design parameter. The research achievements will provide theoretical support for establishing the storey damage model of SRC frame-RC core wall hybrid structure under seismic excitation.

Damage Sensitivity Analysis for Main Design Parameters of Steel Reinforced Concrete Column

2011 ◽  
Vol 374-377 ◽  
pp. 2566-2569
Author(s):  
Shan Suo Zheng ◽  
Yi Hu ◽  
Qing Lin Tao ◽  
Zhi Qiang Li
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Seismic Wave ◽  
Wave Energy ◽  
Design Parameters ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Main Design ◽  
Steel Reinforced Concrete ◽  
Energy Dissipation Capacity

As an indispensable force component to composite structure, the seismic wave energy inputted into integral structure is dissipated by damping force working and plastic hysteresis of steel reinforced concrete column which is taken as research object. According to the condition that the SRC column is mainly used to dissipate the seismic wave energy, the ultimate energy dissipation capacity of SRC column subjected to cyclic loading is taken as the damage characterization. Based on the related theoretical analysis and experimental research, the method for calculating ultimate energy dissipation capacity of SRC column is proposed and the damage sensitivity of various design parameters which contain the section dimension, concrete strength degree and steel ratio are analyzed, then the influence laws of main design parameters impacted on damage evolution of SRC column are revealed in this paper. The research shows that sectional dimension is the most sensitive factor in the damage of SRC column and the steel ratio takes the second place, and then the strength of concrete is the most insensitive design parameter. The achievements will provide theoretical support for establishing the storey damage model of SRC frame structure under seismic excitation.

scholarly journals Optimization of the Curved Metal Damper to Improve Structural Energy Dissipation Capacity

Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 67
Author(s):  
Young-Chan Kim ◽  
Seyed Javad Mortazavi ◽  
Alireza Farzampour ◽  
Jong-Wan Hu ◽  
Iman Mansouri ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Shape Optimization ◽  
Specific Area ◽  
Material Model ◽  
Optimization Techniques ◽  
Hysteretic Behavior ◽  
Design Parameters ◽  
Fe Model ◽  
Constitutive Material Model ◽  
Energy Dissipation Capacity

Structural curved metal dampers are implemented in various applications to mitigate the damages at a specific area efficiently. A stable and saturated hysteretic behavior for the in-plane direction is dependent on the shape of a curved-shaped damper. However, it has been experimentally shown that the hysteretic behavior in the conventional curved-shaped damper is unstable, mainly as a result of bi-directional deformations. Therefore, it is necessary to conduct shape optimization for curved dampers to enhance their hysteretic behavior and energy dissipation capability. In this study, the finite element (FE) model built in ABAQUS, is utilized to obtain optimal shape for the curved-shaped damper. The effectiveness of the model is checked by comparisons of the FE model and experimental results. The parameters for the optimization include the curved length and shape of the damper, and the improved approach is conducted by investigating the curved sections. In addition, the design parameters are represented by B-spline curves (to ensure enhanced system performance), regression analysis is implemented to derive optimization formulations considering energy dissipation, constitutive material model, and cumulative plastic strain. Results determine that the energy dissipation capacity of the curved steel damper could be improved by 32% using shape optimization techniques compared to the conventional dampers. Ultimately, the study proposes simple optimal shapes for further implementations in practical designs.

Justification of design parameters of the fractional reaping conveyor and its devices for removal of beveled stems from under the wheels of the vehicle

2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych
Keyword(s):  
Optimal Design ◽  
Technological Process ◽  
Design Parameters ◽  
Theoretical Studies ◽  
Optimal Parameters ◽  
Belt Conveyor ◽  
Grain Crops ◽  
Mode Of Operation ◽  
Optimal Values ◽  
Main Component

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.

scholarly journals Optimal Design Parameters for a Phased Array Based Ultrasonic Polar Scan

2021 ◽  
pp. 1-1
Author(s):  
Jannes Daemen ◽  
Arvid Martens ◽  
Mathias Kersemans ◽  
Erik Verboven ◽  
Steven Delrue ◽  
...  
Keyword(s):  
Optimal Design ◽  
Phased Array ◽  
Design Parameters ◽  
Ultrasonic Polar Scan
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