Vol.120, No.3, 2019-Table of Contents

  • Integration of Peridynamic Theory and OpenSees for Solving Problems in Civil Engineering
  • Abstract Peridynamics (PD) is a powerful method to simulate the discontinuous problems in civil engineering. However, it may take a lot of effort to implement the material constitutive models into PD program for solving a broad range of problems. OpenSees is an open source software which includes a versatile material library and has been widely used by researchers and engineers in civil engineering. In this context, the paper presents a simple but effective approach to integrate PD with OpenSees by using a Client-Server (CS) software integration technique, such that the existing material constitutive models in OpenSees can be directly used by… More
  •   Views:292       Downloads:190        Download PDF
  • Rotational Friction Damper’s Performance for Controlling Seismic Response of High Speed Railway Bridge-Track System
  • Abstract CRTS-II slab ballastless track on bridge is a unique system in China high speed railway. The application of longitudinal continuous track system has obviously changed dynamic characteristics of bridge structure. The bridge system and CRTS-II track system form a complex nonlinear system. To investigate the seismic response of high speed railway (HSR) simply supported bridge-track system, nonlinear models of three-span simply supported bridge with piers of different height and CRTS-II slab ballastless track system are established. By seismic analysis, it is found that shear alveolar in CRTS-II track system is more prone to be damaged than bridge components, such as… More
  •   Views:349       Downloads:252        Download PDF
  • Probabilistic Performance-Based Optimum Seismic Design Framework: Illustration and Validation
  • Abstract In the field of earthquake engineering, the advent of the performance-based design philosophy, together with the highly uncertain nature of earthquake ground excitations to structures, has brought probabilistic performance-based design to the forefront of seismic design. In order to design structures that explicitly satisfy probabilistic performance criteria, a probabilistic performance-based optimum seismic design (PPBOSD) framework is proposed in this paper by extending the state-of-the-art performance-based earthquake engineering (PBEE) methodology. PBEE is traditionally used for risk evaluation of existing or newly designed structural systems, thus referred to herein as forward PBEE analysis. In contrast, its use for design purposes is limited… More
  •   Views:313       Downloads:248        Download PDF
  • Numerical Modeling Strategy for the Simulation of Nonlinear Response of Slender Reinforced Concrete Structural Walls
  • Abstract A three-dimensional nonlinear modeling strategy for simulating the seismic response of slender reinforced concrete structural walls with different cross-sectional shapes is presented in this paper. A combination of nonlinear multi-layer shell elements and displacement-based beam-column elements are used to model the unconfined and confined parts of the walls, respectively. A uniaxial material model for reinforcing steel bars that includes buckling and low-cyclic fatigue effects is used to model the longitudinal steel bars within the structural walls. The material model parameters related to the buckling length are defined based on an analytical expression for reinforcing steel bars embedded in reinforced concrete… More
  •   Views:425       Downloads:459        Download PDF
  • OpenSees Three-Dimensional Computational Modeling of Ground-Structure Systems and Liquefaction Scenarios
  • Abstract The OpenSees computational platform has allowed unprecedented opportunities for conducting seismic nonlinear soil-structure interaction simulations. On the geotechnical side, capabilities such as coupled solid-fluid formulations and nonlinear incremental-plasticity approaches allow for representation of the involved dynamic/seismic responses. This paper presents recent research that facilitated such endeavors in terms of response of ground-foundation-structure systems using advanced material modeling techniques and high-performance computing resources. Representative numerical results are shown for large-scale soil-structure systems, and ground modification liquefaction countermeasures. In addition, graphical user interface enabling tools for routine usage of such 3D simulation environments are presented, as an important element in support of… More
  •   Views:410       Downloads:321        Download PDF
  • The Behavior of Rectangular and Circular Reinforced Concrete Columns Under Biaxial Multiple Excitation
  • Abstract The aim of this study is to investigate the dynamic performance of rectangular and circular reinforced concrete (RC) columns considering biaxial multiple excitations. For this purpose, an advanced nonlinear finite element model which can simulate various features of cyclic degradation in material and structural components is used. The implemented nonlinear fiber beam-column model accounts for inelastic buckling and low-cycle fatigue degradation of longitudinal reinforcement and can simulate multiple failure modes of RC columns under dynamic loading. Hypothetical rectangular and circular columns are used to investigate the failure modes of RC columns. A detailed ground motion selection is implemented to generate… More
  •   Views:309       Downloads:234        Download PDF
  • Real-Time Hybrid Simulation of Seismically Isolated Structures with Full-Scale Bearings and Large Computational Models
  • Abstract Hybrid simulation can be a cost effective approach for dynamic testing of structural components at full scale while capturing the system level response through interactions with a numerical model. The dynamic response of a seismically isolated structure depends on the combined characteristics of the ground motion, bearings, and superstructure. Therefore, dynamic full-scale system level tests of isolated structures under realistic dynamic loading conditions are desirable towards a holistic validation of this earthquake protection strategy. Moreover, bearing properties and their ultimate behavior have been shown to be highly dependent on rate-of-loading and scale size effects, especially under extreme loading conditions. Few… More
  •   Views:302       Downloads:215        Download PDF
  • Structural Finite Element Software Coupling Using Adapter Elements
  • Abstract This paper describes a versatile and computationally efficient method for coupling several finite element analysis (FEA) programs together so that the unique modeling and analysis capabilities of each code can be utilized simultaneously to simulate the static or dynamic response of a complete numerical system. An arbitrary number of finite element analysis software packages can be coupled by adding two special types of elements, namely generic and adapter elements, to each of the finite element applications using their programming interface. These elements are inserted at the interfaces between the different sub-domains of the complete system modeled by each finite element… More
  •   Views:443       Downloads:223        Download PDF
  • Coupling of Peridynamics and Numerical Substructure Method for Modeling Structures with Local Discontinuities
  • Abstract Peridynamics (PD) is a widely used theory to simulate discontinuities, but its application in real-world structural problems is somewhat limited due to the relatively low-efficiency. The numerical substructure method (NSM) presented by the authors and co-workers provides an efficient approach for modeling structures with local nonlinearities, which is usually restricted in problems of continuum mechanics. In this paper, an approach is presented to couple the PD theory with the NSM for modeling structures with local discontinuities, taking advantage of the powerful capability of the PD for discontinuities simulation and high computational efficiency of the NSM. The structure is simulated using… More
  •   Views:284       Downloads:222        Download PDF
  • Numerical Simulation of a New 3D Isolation System Designed for a Facility with Large Aspect Ratio
  • Abstract This paper proposes a novel three-dimensional (3D) isolation system for facilities and presents the numerical simulation approach for the isolated system under earthquake excitations and impact effect using the OpenSees (Open System for Earthquake Engineering Simulation) software frame work. The 3D isolators combine the quasi-zero stiffness (QZS) system in the vertical direction and lead rubber bearing in the horizontal direction. Considering the large aspect ratio of the isolated facility, linear viscous dampers are designed in the vertical direction to diminish the overturning effect. The vertical QZS isolation system is characterized by a cubic force-displacement relation, thus, no elements or materials… More
  •   Views:268       Downloads:191        Download PDF
  • Experiment and Simulation for Controlling Propagation Direction of Hydrofracture By Multi-Boreholes Hydraulic Fracturing
  • Abstract Hydraulic fracturing has been applied to enhance CBM production and prevent gas dynamical hazard in underground coal mines in China. However, affected by in situ stress orientation, hydrofracture can hardly continuously propagate within coal seam but may easily extend to the adjacent roof-floor strata, causing ineffective permeability enhancement in coal seam and increasing the risk of gas transfinite during mining coal. Thus, it is very necessary to artificially control the propagation direction of hydrofracture and make it well-aligned in large scale in coal seam. In this study, a method for controlling propagation direction of hydrofracture by multi-boreholes is investigated by… More
  •   Views:252       Downloads:178        Download PDF
  • Determination of Working Pressure for Airport Runway Rubber Mark Cleaning Vehicle Based on Numeric Simulation
  • Abstract In this paper, numeric simulations are performed for three dimension models built according to actual surface cleaner in airport runway rubber mark cleaning vehicle using ANSYS FLUENT software on the basis of previous research finished by the authors. After analyzing the simulated flow fields under different standoff distances between nozzle outlet and runway surface and different discharge pressures at nozzle outlet, the relationships of normal stress and shear stress at striking point to outlet pressure and standoff distance are obtained. Finally, the most appropriate discharge pressure at nozzle outlet for the studied surface cleaner model is found, and this will… More
  •   Views:213       Downloads:145        Download PDF