scholarly journals Investigation on Seismic Behaviour of Masonry Infilled Self-Centring-Beam Moment-Frames using New Infill Material Model

2021 ◽  
Author(s):  
Xiaogang Huang ◽  
Zhen Zhou ◽  
yuhang wang
Keyword(s):  
Material Model ◽  
Dynamic Responses ◽  
Moment Frames ◽  
Seismic Behaviour ◽  
Residual Drift ◽  
Equivalent Strut ◽  
Proposed Model ◽  
Load Carrying ◽  
Nonlinear Dynamic Analyses ◽  
Infill Material

Abstract This paper conducted experimental and numerical investigations on seismic behaviour of masonry infilled self-centring-beam moment-frames (SCB-MFs). First, an efficient hysteretic material model was proposed for use with the equivalent strut modelling approach of infill walls. This model was defined by backbone parameters and hysteretic parameters and implemented in the OpenSees platform to facilitate its application. Then, an approximately half-scale test of infilled SCB-MFs was carried out. The test observations and load-carrying capacities of masonry walls in the specimen were reported and analysed. The experimental hysteresis was reproduced by the numerical model using the proposed infill material. Finally, structural analyses were conducted for 3-, 6-, 9-, and 12-storey infilled SCB-MFs based on the calibrated computational model. Comparisons of the hysteretic behaviours obtained by the simulation with experimental results showed that the proposed infill material could capture the strength, stiffness, and energy dissipation during reloading, along with the residual drift during unloading. The nonlinear dynamic analyses also validated the feasibility of using the proposed model to simulate the dynamic responses of infilled SCB-MFs.

scholarly journals Lane Departure Warning Estimation Using Yaw Acceleration

2020 ◽  
Vol 11 (1) ◽  
pp. 102-111
Author(s):  
Em Poh Ping ◽  
J. Hossen ◽  
Wong Eng Kiong
Keyword(s):  
Vehicle Dynamics ◽  
Dynamic Responses ◽  
Dynamics Simulation ◽  
Steering Wheel ◽  
Mathematical Representation ◽  
Vehicle Speed ◽  
Lane Departure Warning ◽  
Model Based ◽  
Lane Departure ◽  
Proposed Model

AbstractLane departure collisions have contributed to the traffic accidents that cause millions of injuries and tens of thousands of casualties per year worldwide. Due to vision-based lane departure warning limitation from environmental conditions that affecting system performance, a model-based vehicle dynamics framework is proposed for estimating the lane departure event by using vehicle dynamics responses. The model-based vehicle dynamics framework mainly consists of a mathematical representation of 9-degree of freedom system, which permitted to pitch, roll, and yaw as well as to move in lateral and longitudinal directions with each tire allowed to rotate on its axle axis. The proposed model-based vehicle dynamics framework is created with a ride model, Calspan tire model, handling model, slip angle, and longitudinal slip subsystems. The vehicle speed and steering wheel angle datasets are used as the input in vehicle dynamics simulation for predicting lane departure event. Among the simulated vehicle dynamic responses, the yaw acceleration response is observed to provide earlier insight in predicting the future lane departure event compared to other vehicle dynamics responses. The proposed model-based vehicle dynamics framework had shown the effectiveness in estimating lane departure using steering wheel angle and vehicle speed inputs.

scholarly journals Flexural behavior of composite structural insulated panels with magnesium oxide board facings

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Łukasz Smakosz ◽  
Ireneusz Kreja ◽  
Zbigniew Pozorski
Keyword(s):  
Magnesium Oxide ◽  
Material Model ◽  
Expanded Polystyrene ◽  
Flexural Behavior ◽  
Joint Analysis ◽  
Model Parameters ◽  
Fe Model ◽  
Computational Results ◽  
Four Point Bending ◽  
Proposed Model

Abstract The current report is devoted to the flexural analysis of a composite structural insulated panel (CSIP) with magnesium oxide board facings and expanded polystyrene (EPS) core, that was recently introduced to the building industry. An advanced nonlinear FE model was created in the ABAQUS environment, able to simulate the CSIP’s flexural behavior in great detail. An original custom code procedure was developed, which allowed to include material bimodularity to significantly improve the accuracy of computational results and failure mode predictions. Material model parameters describing the nonlinear range were identified in a joint analysis of laboratory tests and their numerical simulations performed on CSIP beams of three different lengths subjected to three- and four-point bending. The model was validated by confronting computational results with experimental results for natural scale panels; a good correlation between the two results proved that the proposed model could effectively support the CSIP design process.

Evolutive Laws and Constitutive Relations in Nonlocal Viscoplasticity

2012 ◽  
Vol 152-154 ◽  
pp. 990-996 ◽  
Author(s):  
Fabio de Angelis
Keyword(s):  
Constitutive Relations ◽  
Material Model ◽  
Standard Material ◽  
Viscoplastic Model ◽  
Proposed Model

In the present work the evolutive laws and the constitutive relations for a model of nonlocal viscoplasticity are analyzed. Nonlocal dissipative variables and suitable regularization operators are adopted. The proposed model is developed within the framework of the generalized standard material model. Suitable forms of the elastic and dissipative viscoplastic potentials are defined and the associated constitutive relations are specialized. The evolutive laws for the proposed nonlocal viscoplastic model are presented in a general form which can be suitably specialized in order to include different models of nonlocal viscoplasticity.

Dynamic damage assessment of float glass under blast loading

2019 ◽  
Vol 22 (11) ◽  
pp. 2517-2529
Author(s):  
Xiao-Qing Zhou ◽  
Ming-Yu Wang ◽  
Li-Xiao Li
Keyword(s):  
Damage Assessment ◽  
High Speed ◽  
Blast Loading ◽  
Material Model ◽  
The United States ◽  
Float Glass ◽  
Dynamic Responses ◽  
Kinematic Equation ◽  
Finite Element Software ◽  
Dynamic Damage

Architectural glass, especially the float glass, is a fragile part of a building. The architectural glass becomes a large amount of high-speed flying debris under bomb attacks and accidental explosions, thereby causing serious threat to residents. This study investigates the dynamic responses of a normal float glass subjected to blast loading using the explicit dynamic finite element software LS-DYNA. A JH-2 material model, which considers the strain rate effect and damage accumulation, is adopted for the float glass. A preliminary study shows that the present numerical model combined with reasonable material parameters can simulate the failure mode of the glass and the ejection velocity of glass fragments after failure. The verified model is then used to investigate the dynamic damage responses of the float glass under different loading cases. The damage assessment criterion of float glass is established on the basis of the glazing protection levels defined by the General Services Administration of the United States. Comprehensive simulations are conducted on different amounts of explosive and standoff distances. The degrees of glass damage under different loading cases are determined by combining the projection velocity of glass fragments after failure with a kinematic equation. Finally, the damage assessment diagram of float glass under different amounts of explosive is presented and compared with those in FEMA 426.

scholarly journals Nonlinear Dynamic Characteristic Analysis of a Landing String in Deepwater Riserless Drilling

2018 ◽  
Vol 2018 ◽  
pp. 1-17
Author(s):  
Jun Liu ◽  
Hongliang Zhao ◽  
Simon X. Yang ◽  
Qingyou Liu ◽  
Guorong Wang
Keyword(s):  
Boundary Condition ◽  
Dynamic Model ◽  
Marine Environment ◽  
Lower Boundary ◽  
Dynamic Responses ◽  
Characteristic Analysis ◽  
Lower Boundary Condition ◽  
Response Characteristics ◽  
Proposed Model ◽  
Nonlinear Dynamic Characteristic

The landing string is an important component of deepwater riserless drilling systems. Determination of the dynamic characteristics of the landing string plays an essential role in its design for ensuring its safe operation. In this paper, a dynamic model is developed to investigate the dynamic response characteristics of a landing string, where a landing string in a marine environment is modeled as a flexible slender tube undergoing coupled transverse and axial motions. The heaving motion of the drilling platform is taken as the upper boundary condition and the motion of the drilling bit caused by the interaction between the rock and the bit as the lower boundary condition. A semiempirical Morison equation is used to simulate the effect of the load imposed by the marine environment. The dynamic model, which is nonlinearly coupled and multibody, is discretized by a finite element method and solved by the Newmark technique. Using the proposed model, the dynamic responses of the displacement, axial force, and moment in the landing string are investigated in detail to find out the influences of driving depth of surface catheter, platform motion, bit movement, and marine environment on the dynamical characteristics of the landing string.

Implementation and Verification of a Masonry Infill Model Considering the Out-Of-Plane Behaviour

2013 ◽  
Vol 353-356 ◽  
pp. 1836-1845
Author(s):  
Zhi Xiong Chen ◽  
Ying Hu
Keyword(s):  
Numerical Model ◽  
Inertial Forces ◽  
Plane Failure ◽  
Masonry Infill ◽  
Earthquake Loads ◽  
Equivalent Strut ◽  
Column Type ◽  
Proposed Model ◽  
Out Of Plane ◽  
Plane Direction

The response of reinforced concrete buildings to earthquake loads can be substantially affected by the influence of infill walls. Also the out-of-plane failure of the infill can cause heavy casualties. In this article, an improved numerical model for the simulation of the in-plane and out-of-plane behaviour of masonry infill is proposed. First, the proposed model is presented. This is an upgrading equivalent strut model composed of two beam-column type elements, with a node at the mid-span assigned a mass in the in-plane and the out-of-plane direction to account for the inertial forces in both directions. Second, the main results of the calibration analyses obtained with two experiments are presented and discussed.

Dynamic Analysis of a Cylindrical Roller Bearing With Time-Varying Localized Defects on Raceways

2015 ◽  
Author(s):  
Fengtao Wang ◽  
Li Chen ◽  
Heng Liu ◽  
Minqing Jing ◽  
Wei Chen ◽  
...  
Keyword(s):  
Roller Bearing ◽  
Step Function ◽  
Dynamic Responses ◽  
Experimental Comparison ◽  
Time Varying ◽  
Proposed Model ◽  
Time Domains ◽  
Localized Defects ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

An existing defect on the bearing raceway may evolve with the interactions between the bearing elements, and the evolutions of the defect may be divided into different stages. In this study, a dynamic model for a cylindrical roller bearing with localized defects on raceways is developed to investigate vibration character of the bearing in these stages. The coupling of centrifugal forces, gravity forces and the slipping of the roller are considered. The half sine function and step function are used to construct time-varying models of defects in different stages, which is reflected on the local deflection. The system dynamic equations are solved by the fourth-order Runge-Kutta integration method with variable steps. Time domains and frequency domains are used to analyze dynamic responses of the bearing in every defect stage, which can be used as a reference of fault diagnosis. An experimental comparison in the previous study is carried out to validate the proposed model.

scholarly journals Nonlinear Material Model for Quasi-Unidirectional Woven Composite Accounting for Viscoelastic, Viscous Deformation, and Stiffness Reduction

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 903 ◽  
Author(s):  
Zhanyu Zhai ◽  
Bingyan Jiang ◽  
Dietmar Drummer
Keyword(s):  
Material Model ◽  
Tensile Tests ◽  
Experimental Results ◽  
Nonlinear Material ◽  
Weibull Function ◽  
Viscous Deformation ◽  
Stiffness Reduction ◽  
Viscoelastic Strain ◽  
Proposed Model ◽  
The Individual

To clarify the individual contribution of viscoelastic and viscous deformation to the global nonlinear response of composites, multilevel cyclic loading-unloading recovery tensile tests were carried out. The experimental results show that there is a linear relationship between the viscous strain and viscoelastic strain of composites, regardless of the off-axis angle or loading stress level. On the basis of experimental results, a coupled damage-plasticity constitutive model was proposed. In this model, the plasticity theory was adopted to assess the evolution of viscous strains. The viscoelastic strain was represented as a linear function of viscous strains. Moreover, the Weibull function of the effective stress was introduced to evaluate the damage variables in terms of stiffness reduction. The tensile stress-strain curves, predicted by the proposed model, showed a good agreement with experimental results.

scholarly journals A Simplified Approach for the Hydro-Forming Process of Bi-Metallic Composite Pipe

2017 ◽  
Vol 62 (2) ◽  
pp. 879-883 ◽  
Author(s):  
M. Zheng ◽  
H. Gao ◽  
H. Teng ◽  
J. Hu ◽  
Z. Tian ◽  
...  
Keyword(s):  
Residual Stress ◽  
Plastic Material ◽  
Material Model ◽  
Forming Process ◽  
Simplified Approach ◽  
Metallic Composite ◽  
Perfectly Plastic ◽  
Proposed Model ◽  
Composite Pipe ◽  
Elastic Perfectly Plastic

AbstractIn this article, it aims to propose effective approaches for hydro-forming process of bi-metallic composite pipe by assuming plane strain and elastic-perfectly plastic material model. It derives expressions for predicting hydro-forming pressure and residual stress of the forming process of bi-metallic composite pipe. Test data from available experiments is employed to check the model and formulas. It shows the reliability of the proposed model and formulas impersonally.

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