Evaluating the Effect of Buckling-Restrained Brace Model on Seismic Structural Responses

2017 ◽  
Vol 11 (02) ◽  
pp. 1750002 ◽  
Author(s):  
Yulong Feng ◽  
Jing Wu ◽  
Chunlin Wang ◽  
Shaoping Meng
Keyword(s):  
Kinematic Hardening ◽  
Stiffness Ratio ◽  
Braced Frames ◽  
Simplified Models ◽  
Buckling Restrained Brace ◽  
Perfectly Plastic ◽  
Seismic Design Code ◽  
Structural Responses ◽  
Buckling Restrained Braced Frames ◽  
Elastic Perfectly Plastic

Numerical simulation is an important measure to study the seismic performance of buckling-restrained braced frames (BRBFs). Practically, some simplified models, such as the elastic–plastic with kinematic hardening model and the elastic perfectly-plastic model, are used to simulate the behavior of buckling-restrained brace (BRBs). To provide structural engineers the reference of errors when simplified models are used, this paper comparatively evaluates the effect of the BRB model on seismic structural responses using the OpenSees software. A comparison is made on six-storey and 16-storey BRBFs with rigid beam-to-column connections; these are designed according to Chinese seismic design code. Moreover, the effects of the post-yielding stiffness ratio of frame [Formula: see text] and the stiffness ratio of BRB to frame [Formula: see text] on the errors are specifically investigated through a parametric study of both BRBFs. The results show that the seismic response average errors of the simplified models are mostly less than 5%, which satisfies the engineering requirements.

An Improved Thermo-Ratcheting Boundary of Pressure Pipeline

2016 ◽  
Vol 725 ◽  
pp. 311-315
Author(s):  
Qian Hua Kan ◽  
Jian Li ◽  
Han Jiang ◽  
Guo Zheng Kang
Keyword(s):  
Mechanical Stress ◽  
Nuclear Power ◽  
Kinematic Hardening ◽  
Constitutive Models ◽  
Plastic Strain Increment ◽  
Perfectly Plastic ◽  
Axial Tensile ◽  
Thermal Ratcheting ◽  
Pressure Pipeline ◽  
Elastic Perfectly Plastic

The thermal ratcheting boundary of pressure pipeline is a popular topic in nuclear power engineering. The existed thermal ratcheting boundary based on the Bree diagram is conservative for structures subjected to the thermo-mechanically coupled loadings since it was obtained only from an elastic-perfectly plastic model. Therefore, it is necessary to improve the existed thermal ratcheting boundary based on a reasonable constitutive model. The Bree diagram was validated firstly by the linear relationship between the plastic strain increment and mechanical stress by finite element method. And then the influences of different constitutive models, such as elastic-perfectly plastic, multi-linear kinematic hardening, Chaboche and Abdel Karim-Ohno models, on the thermal ratcheting boundary of pressure pipeline were investigated numerically. It is found that the elastic-perfectly plastic and multi-linear kinematic hardening models provide the lower and upper bounds for the thermal ratcheting boundary, respectively. Finally, an improved thermal ratcheting boundary by introducing the dimensionless axial tensile stress was proposed based on the Bree diagram, the improved thermal ratcheting boundary covered the present cases with different ratios of mechanical stress over thermal stress.

How Many Records Should be used in an ASCE/SEI-7 Ground Motion Scaling Procedure?

2012 ◽  
Vol 28 (3) ◽  
pp. 1223-1242 ◽  
Author(s):  
Juan C. Reyes ◽  
Erol Kalkan
Keyword(s):  
Ground Motions ◽  
Accurate Estimate ◽  
Perfectly Plastic ◽  
History Analysis ◽  
Scaling Procedure ◽  
Response History Analysis ◽  
Nonlinear Response History Analysis ◽  
Structural Responses ◽  
Ground Motion Scaling ◽  
Elastic Perfectly Plastic

U.S. national building codes refer to the ASCE/SEI-7 provisions for selecting and scaling ground motions for use in nonlinear response history analysis of structures. Because the limiting values for the number of records in the ASCE/SEI-7 are based on engineering experience, this study examines the required number of records statistically, such that the scaled records provide accurate, efficient, and consistent estimates of “true” structural responses. Based on elastic–perfectly plastic and bilinear single-degree-of-freedom systems, the ASCE/SEI-7 scaling procedure is applied to 480 sets of ground motions; the number of records in these sets varies from three to ten. As compared to benchmark responses, it is demonstrated that the ASCE/SEI-7 scaling procedure is conservative if fewer than seven ground motions are employed. Utilizing seven or more randomly selected records provides more accurate estimate of the responses. Selecting records based on their spectral shape and design spectral acceleration increases the accuracy and efficiency of the procedure.

Elasto-Plastic Finite Element Analyses of Two-Dimensional Rolling and Sliding Contact Deformation of Bearing Steel

1989 ◽  
Vol 111 (2) ◽  
pp. 309-314 ◽  
Author(s):  
A. M. Kumar ◽  
G. T. Hahn ◽  
V. Bhargava ◽  
C. Rubin
Keyword(s):  
Finite Element ◽  
Rail Steel ◽  
Kinematic Hardening ◽  
High Hardness ◽  
High Strength ◽  
Bearing Steel ◽  
Sliding Contact ◽  
Plastic Behavior ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

In the past, the mechanics of repeated rolling and sliding contact could only be treated for the idealized, elastic-perfectly-plastic (and isotropic) cyclic materials behavior, albeit approximately. They have not proven useful because the real cyclic plastic behavior of contacting materials is anything but perfectly plastic or isotropic. Using finite element methods, the authors have developed techniques for treating elastic-linear-kinematic hardening-plastic (ELKP) behavior, an idealization that comes much closer to the behavior of low, medium, and high hardness steels. In an earlier paper, the authors have examined rolling and sliding on rail steel, which is much softer than hardened bearing steel and displays quite different ELKP properties. The present paper offers the first results for repeated rolling and sliding for high strength bearing steel ELKP behavior and material properties.

Finite Element Based Unloading of an Elastic Plastic Spherical Stick Contact for Varying Tangent Modulus and Hardening Rule

2013 ◽  
Vol 1 (1) ◽  
pp. 13-32
Author(s):  
Biplab Chatterjee ◽  
Prasanta Sahoo
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Kinematic Hardening ◽  
Tangent Modulus ◽  
Isotropic Hardening ◽  
Finite Element Software ◽  
Perfectly Plastic ◽  
Hardening Models ◽  
Qualitative Similarity ◽  
Elastic Perfectly Plastic

Loading-unloading behavior of a deformable sphere with a rigid flat under full stick contact condition is investigated for varying strain hardening. The study considers various tangent modulus using the finite element software ANSYS. Both the bilinear kinematic hardening and isotropic hardening models are considered. Numerical simulation reveals the qualitative similarity between kinematic and isotropic hardening regarding the variation of interfacial parameters during loading-unloading for various tangent modulus. It is found that the material with kinematic hardening dissipates more energy than the material with isotropic hardening during unloading. However for elastic perfectly plastic material, the loading-unloading behavior is insensitive to hardening model.

Inelastic behavior of smart recentering buckling-restrained braced frames with superelastic shape memory alloy bracing systems

2012 ◽  
Vol 227 (4) ◽  
pp. 806-818 ◽  
Author(s):  
Jong Wan Hu ◽  
Dong Ho Choi ◽  
Dong Keon Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Large Strains ◽  
Self Healing ◽  
Inelastic Behavior ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Buckling Restrained Brace ◽  
Buckling Restrained Braced Frames ◽  
Brace Frames

Buckling-restrained braced frames are steadily replacing concentrically braced frames because buckling-restrained brace can yield without buckling when subjected to both tension and compression. Though buckling-restrained brace frames are being widely used as framing structures for construction in high seismicity areas, it is shown that at large strains, a considerable amount of permanent deformation is produced at the support connector between the brace and the frame. This drawback can be overcome by providing recentering capabilities to the braced frame system. By applying the concept of a recentering system to the design of buckling-restrained brace frames, we developed braced frames that incorporate buckling-restrained braces with superelastic shape memory alloy end-support connectors. Owing to the recentering capability, shape memory alloy materials have been used in the place where large deformation may feasibly occur. The primary advantages of the innovative braced frames proposed herein are verified through nonlinear pushover analyses. Analytical frame models are developed to estimate theultimate and residual inter-story drifts. The analysis results suggest that buckling-restrained brace frames with superelastic shape memory alloy bracing systems are more effective in controlling residual inter-story drifts than those with conventional steel bracing systems owing to the inherent self-healing characteristics of superelastic shape memory alloys.

scholarly journals Numerical Investigation of Seismic Response of Hybrid Buckling Restrained Braced Frames

2018 ◽  
Author(s):  
Nader Hoveidae
Keyword(s):  
Stainless Steel ◽  
Ground Motions ◽  
Residual Deformation ◽  
Core Material ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
The Core ◽  
Buckling Restrained Brace ◽  
Buckling Restrained Braces ◽  
Buckling Restrained Braced Frames

The Conventional buckling restrained braces used in concentrically braced frames are expected to yield in both tension and compression without major degradation of capacity under severe seismic ground motions. One of the weakness points of a standard buckling restrained braced frame is the low post-yield stiffness and thus large residual deformation under moderate to severe ground motions. This phenomenon can be related to the low post-yield stiffness of the core segment in comparison to its elastic stiffness. This paper investigates the application of stainless steel as the core material in a hybrid buckling restrained brace. The “hybrid” term arises from the use of more than one core component with different steel materials, including high strength high-performance steel and stainless steel (304L) with high strain hardening in the core of buckling restrained brace. Nonlinear dynamic time history analyses were conducted on a variety of diagonally braced frames with different heights, in order to compare the seismic performance of standard (non-hybrid) and hybrid buckling restrained braced frames. The results showed that the proposed hybrid buckling restrained braces reduce the inter-story and specially the residual drift demands in buckling restrained braced frames.

Study on Dynamic Response by Alternating and Static Load

2016 ◽  
Author(s):  
Akihito Otani ◽  
Satoru Kai
Keyword(s):  
Dynamic Load ◽  
Static Load ◽  
Inertia Force ◽  
Plastic Collapse ◽  
Nuclear Facilities ◽  
Perfectly Plastic ◽  
Seismic Design Code ◽  
Seismic Force ◽  
Elastic Perfectly Plastic ◽  
Seismic Forces

An inertia force in a seismic response of structure excited by an earthquake generates the seismic force acting on the structure. The handling of seismic forces has been being discussed in terms of how the seismic force on a piping controls the deformation of the piping, load-controlled or displacement-controlled. A seismic design code for nuclear facilities applied in Japan qualifies this kind of seismic forces as primary stress components which shall be limited to prevent any plastic collapse, on the assumption that the seismic force mainly consists of load-controlled loads and the deformation due to earthquakes is caused by the loads. The authors studied about a condition of plastic collapse occurrence by the relationship between response acceleration and displacement of SDOF system. And it was represented in a previous paper that plastic collapse hardly occurred to soft structure due to an inertia force generated from response acceleration tended to oppose a response displacement. Several elastic plastic response analyses of elastic-perfectly-plastic SDOF model are performed with applying dynamic load and both of dynamic load and static load. By the results of the analyses, three forces, which are inertia force, element force and external force, are investigated the relations against the deformation.

Drift-based seismic design procedure for Buckling Restrained Braced Frames

Structures ◽  
2021 ◽  
Vol 30 ◽  
pp. 62-74
Author(s):  
Seyed Amin Mousavi ◽  
Seyed Mehdi Zahrai ◽  
Ali Akhlagh Pasand
Keyword(s):  
Seismic Design ◽  
Design Procedure ◽  
Braced Frames ◽  
Buckling Restrained Braced Frames

scholarly journals A FEM analysis of the settlement of a tall building situated on loess subsoil

2020 ◽  
Vol 10 (1) ◽  
pp. 519-526
Author(s):  
Krzysztof Nepelski
Keyword(s):  
Fem Analysis ◽  
Actual Process ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Modified Cam Clay ◽  
Linear Behaviour ◽  
Subsequent Calculation ◽  
Elastic Perfectly Plastic ◽  
Subsoil Model ◽  
Storey Building

AbstractIn order to correctly model the behaviour of a building under load, it is necessary to take into account the displacement of the subsoil under the foundations. The subsoil is a material with typically non-linear behaviour. This paper presents an example of the modelling of a tall, 14-storey, building located in Lublin. The building was constructed on loess subsoil, with the use of a base slab. The subsoil lying directly beneath the foundations was described using the Modified Cam-Clay model, while the linear elastic perfectly plastic model with the Coulomb-Mohr failure criterion was used for the deeper subsoil. The parameters of the subsoil model were derived on the basis of the results of CPT soundings and laboratory oedometer tests. In numerical FEM analyses, the floors of the building were added in subsequent calculation steps, simulating the actual process of building construction. The results of the calculations involved the displacements taken in the subsequent calculation steps, which were compared with the displacements of 14 geodetic benchmarks placed in the slab.

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