Multi-story Frame Structures Research Articles

Quantitative Carbon Emission Prediction Model to Limit Embodied Carbon from Major Building Materials in Multi-Story Buildings

As the largest contributor of carbon emissions in China, the building sector currently relies mostly on enterprises’ own efforts to report carbon emissions, which usually results in challenges related to information transparency and workload for regulatory bodies, who play an otherwise vital role in controlling the building sector’s carbon footprint. In this study, we established a novel regulatory model known as QCEPM (Quantitative Carbon Emission Prediction Model) by conducting multiple linear regression analysis using the quantities of concrete, rebar, and masonry structures as independent variables and the embodied carbon emissions of a building as the dependent variable. We processed the data in the detailed quantity list of 20 multi-story frame structure buildings and fed them to the QCEPM for the solution. Comparison of the QCEPM-calculated results against the time-consuming and error-prone manual calculation results suggested a mean absolute percentage error (MAPE) of 2.36%. Using this simplified model, regulatory bodies can efficiently supervise the embodied carbon emissions in multi-story frame structures by setting up a carbon quota for a project in its approval stage, allowing the construction enterprise to carry out dynamic control over the three most important audited building materials throughout a project’s planning and implementation phase.

Performance evaluation and FRP strengthening of concrete-filled steel tubular columns subjected to vehicle impact

Concrete-filled steel tubular (CFST) columns have been widely used in multi-story and high-rise frame structures. During the service period, they may suffer vehicle impact due to traffic accidents or terrorist attacks. This paper numerically evaluates the performance of CFST columns under vehicle impact and investigates the effects of carbon FRP (CFRP) wrapping arrangements on performance improvement of the columns. Before that, a numerical model was developed to simulate the responses of CFST columns without and with FRP wrapping under vehicle impact and post-impact axial compression, and then calibrated by reported tests. Evaluation results show that the performance of CSFT columns under vehicle impact is divided into five levels, i.e., no repair required, rapid repair required, minor repair needed, major repair needed, and replacement needed. The performance level decreases with the increase in the vehicle weight or speed and increases with the increase in the column diameter or steel tube thickness. The column height has little effects on the performance level. A higher axial load ratio, e.g., 0.5, might reduce the performance level. Besides, a CFST column tends to fail in flexure mode when hit by F800 medium truck, while it may fail in flexure & shear mode when hit by C2500 pickup truck. Investigation results indicate that FRP wrapping with each layer orientation of 90° (i.e., in the longitudinal direction) and 0° (i.e., in the hoop direction) present the best performance improvement for a CFST column possibly undergoing flexure & shear and flexure failure, respectively. The increase of the number of FRP layers effectively improves the performance levels of CFST columns but the excessive demand may be not economical. It is not necessary to employ an FRP wrapping range of 100% for improving the vehicular impact performance level of a CFST column to the expected one.

A convolution neural network-based technique for health monitoring of connections of a multi-story 3D steel frame structure

A convolution neural network-based technique for health monitoring of connections of a multi-story 3D steel frame structure

Application of Endurance Time Method in Seismic Assessment of RC Frames Designed by Direct Displacement-Based Procedure

This paper addresses the Direct Displacement-Based Design (DDBD) approach of multi-story RC frame structures consistent with changes ‎to design criteria between Turkish earthquake codes of TSC-2007 and TBEC-2018. The corresponding response modification factor (R) of structures designed based on the DDBD approach is also estimated in this research. The design base shear forces of both codes are compared considering different R factors and also with that of the DDBD approach. The results showed that the DDBD approach, as per TBEC-2018, provides RC frame structures with higher R values compared to the similar approach in accordance with TSC-2007. The Endurance Time (ET) method is a time history-based procedure for seismic assessment of ‎structures ‎under intensifying dynamic excitations aided to judge their performance at various intensity levels. Since, up to now, the ET method has not been considered to evaluate the performance of the structures designed by the DDBD approach, this paper addresses this issue. The ET ‎performance curves of RC frames show that structures designed by the DDBD approach in ‎accordance with TBEC-2018 exhibit higher Interstory Drift Ratios (IDRs) values than TSC-2007 at various hazard levels.

The impact of infill wall distribution on the mechanical behavior and failure patterns of multi-story RC frame structures: An acceleration–strain coupled testing approach

Historically, earthquakes have caused extensive damage to multi-story buildings, often leading to partial or total collapses. Nevertheless, these severely damaged structures rarely exhibit the "strong column–weak beam" failure pattern, and the performance of their vertical load-bearing components varies notably. Our study reveals that the uneven distribution of infill walls leads to divergent mechanical behaviors in columns located at different positions within the frame structure. To address this issue, an acceleration–strain coupled testing system was developed and implemented in a typical reinforced concrete (RC) frame structure of a veranda-style teaching building. This system, utilizing strong-motion seismographs for trigger acquisition, collected synchronized strain data from both columns adjacent to the veranda and those partially constrained by infill walls. Two sets of records were obtained, preliminarily confirming the internal force concentration due to the infill walls' constraints. Furthermore, the varied mechanical behaviors of components along two axes emerge as the primary factors causing significant structural damage and collapse. Based on these characteristic behaviors, quasi-static tests were conducted on frame columns, both unrestricted and partially restricted by infill walls. Results indicate that the constraining effect of the partial infill walls intensifies with deformation, markedly affecting column behavior. Notably, the load-bearing capacity, ductility, and ultimate displacement exhibited substantial differences between the two column types. The coexistence of these mechanically diverse components within the same structure leads to a sequence of failures, thereby altering the mechanisms of structural damage and collapse.

Vibration Control of Metal Spatial Structures With Tuned Mass Dampers

additional-mass-type vibration-control devices, especially TMDs, and confirm their control performance under seismic loadings by both analytical and experimental methods. Firstly, to effectively control spatial structures that have different vibration properties than multi-story frame structures, we propose a spatially distributed MTMD method. This method is characterized by controlling plural modes with closely spaced natural frequencies based on the robust property of the MTMD against variation of natural frequencies. Next, we propose a TMD-with-initial-displacement method to improve transient response. Then, we describe a shaking table test using TMD models and compare test results and analytical results. Lastly, we describe a method of applying a Houde damper system through a real construction project; the Eye of the Yellow Sea Pedestrian Bridge.

DNN-MLVEM: A Data-Driven Macromodel for RC Shear Walls Based on Deep Neural Networks

This study proposes the DNN-MVLEM, a novel macromodel for the non-linear analysis of RC shear walls based on deep neural networks (DNN); while most RC shear wall macromodeling techniques follow a deterministic approach to find the right configuration and properties of the system, in this study, an alternative data-driven strategy is proposed instead. The proposed DNN-MVLEM is composed of four vertical beam-column elements and one horizontal shear spring. The beam-column elements implement the fiber section formulation with standard non-linear uniaxial material models for concrete and steel, while the horizontal shear spring uses a multi-linear force–displacement relationship. Additionally, three calibration factors are introduced to improve the performance of the macromodel. The data-driven component of the proposed strategy consists of a large DNN that is trained to predict the force–displacement curve of the shear spring and the three calibration factors. The training data is created using a parametric microscopic FEM model based on the multi-layer shell element formulation and a genetic algorithm (GA) that optimizes the response of the macromodel to match the behavior of the microscopic FEM model. The DNN-MVLEM is tested in two types of examples, first as a stand-alone model and then as part of a two-bay multi-story frame structure. The results show that the DNN-MVLEM is capable of reproducing the results obtained with the microscopic FEM model up to 100 times faster and with an estimated error lower than 5%.

Dynamic Response and Reliability Analysis of Stochastic Multi-Story Frame Structures under Random Excitation

In earthquake engineering problems, uncertainty exists not only in the seismic excitations but also in the structure's parameters. This study investigates the influence of structural geometry, elastic modulus, mass density, and section dimension uncertainty on the stochastic earthquake response of a multi-story moment resisting frame subjected to random ground motion. The North-south component of the Ali Gharbi earthquake in 2012, Iraq, is selected as ground excitation. Using the power spectral density function (PSD), the two-dimensional finite element model of the moment resisting frame's base motion is modified to account for random ground motion. The probabilistic study of the moment resisting frame structure using stochastic finite element utilizing Monte Carlo simulation was presented using the finite element program ABAQUS. The dynamic reliability and probability of failure of the stochastic and deterministic structure based on the first passage failure were checked and evaluated. Results revealed that the probability of failure increased due to randomness in stiffness and mass of the structure. Generally, natural frequencies for the lower modes of vibration and relative displacements for the lower stories were more sensitive to the randomness in system parameters.

Seismic performance assessment of a multi-story bamboo frame structure

As a building material, engineered bamboo has caught attention around the world due to its advantages in energy conservation and environmental protection. The seismic performance of bamboo buildings needs to be evaluated to further promote the use of bamboo materials in building construction. We studied the seismic response of a 3-story bamboo frame structure numerically using nonlinear dynamic time history analysis. A simplified modeling method for bamboo column-beam joints was proposed in the numerical model. The hysteresis behaviour of the joint was simulated by Pinching 4 material in OpenSEES, with the parameters calibrated through test results. Comparative analysis shows that the proposed modeling method could reasonably reflect the pinching effect and the degradation of the joint hysteretic behavior. A total of 20 ground motions with three intensities were involved in the nonlinear dynamic analysis. The results demonstrate that the frame meets target performance levels, providing evidence for the further popularization of engineered bamboo structures.

Inverse Analysis of Structural Damage Based on the Modal Kinetic and Strain Energies with the Novel Oppositional Unified Particle Swarm Gradient-Based Optimizer

Structural damage inspection is a key structural engineering technique that strives for ensuring structural safety. In this regard, one of the major intelligent approaches is the inverse analysis of structural damage using evolutionary computation. By considering the recent advances in this field, an efficient hybrid objective function that combines the global modal kinetic and modal strain energies is introduced. The newly developed objective function aims to extract maximum dynamic information from the structure and overcome noisy conditions. Moreover, the original methods are usually vulnerable to the associated high multimodality and uncertainty of the inverse problem. Therefore, the oppositional learning (OL) for population initialization and convergence acceleration is first adopted. Thereafter, the unified particle swarm algorithm (UPSO) mechanism is combined with another newly developed algorithm, the gradient-based optimizer (GBO). The new algorithm, called the oppositional unified particle swarm gradient-based optimizer (OL-UPSGBO), with the convergence acceleration feature of (OL), enhances balanced exploration-exploitation of UPSO, and the local escaping operator of GBO is designed to specifically deal with the complex inverse analysis of structural damage problems. To authenticate the performance of the OL-UPSGBO, the complex benchmark set of CEC 2017 is adopted to compare the OL-UPSGBO with several original metaheuristics. Furthermore, the developed approach for structural damage identification is tested using several damage scenarios in a multi-story frame structure. Results show that the developed approach shows superior performance and robust behavior when tackling the inverse analysis of structural damage.

Experimental Dynamic Response of a Multi-Story Frame Structure Equipped with Non-Conventional TMD Implemented via Inter-Story Isolation

A shaking table experiment conducted on a multi-degrees-of-freedom frame structure equipped with a non-conventional tuned mass damper (TMD) is presented. The non-conventional TMD is characterized by a high mass ratio, without adding further structural masses, and is realized via inter-story isolation. The structure top story mass of a four-story steel frame structure is isolated and converted into tuned mass, connecting to the substructure with two high damping rubber bearings placed in series. Aspects related to the dynamic structural response as well as the seismic effectiveness assessment of a non-conventional TMD are addressed. Three structural configurations are tested: the reference four-story structure, the three-story intermediate structure, and the three-story structure equipped with a non-conventional TMD. The input motion conditions considered are: white noise, sine sweep, and natural earthquakes. Through experiments, structural identification is carried out and different dynamic behaviors emerge for the configurations tested. The nonlinear effects provoked on the structure by the adopted isolators are investigated, showing high dissipative capabilities in a wide range of amplitudes of the excitation. It is demonstrated that a non-conventional TMD is a smart control strategy useful for enhancing structural vibration mitigation.

Application of the POD method to nonlinear dynamic analysis of reinforced concrete frame structures subjected to earthquakes

For the purpose of reducing computational cost, this paper presents an extension of the Proper Orthogonal Decomposition method (POD) to nonlinear dynamic analysis of reinforced concrete multistory frame structure. The material nonlinearity, due to plasticity and damaging, is modeled by the multifiber section approach. An initial expensive full model nonlinear time-history analysis is conducted for the frame structure subjected to a portion of an initial seismic base excitation. Then, POD modes are extracted and used to reduce the dynamic model for the rest of the initial base excitation or for multiple different ones. By comparing the full and reduced models, the computational cost was lowered by up to 94 % while maintaining good level of accuracy.

Seismic performance of a steel frame structure with dissipative cladding connections

In this study, a dissipative connection system for multistory steel frame structures is proposed, in which two bearing connectors are located at the top and a metal yielding dissipative connector (i.e., tapered connector) is located at the bottom of a large panel. Quasi-static test was conducted to investigate the performance of individual connectors first. Then two steel subassemblies, one having a steel frame with a large cladding panel and the other as its counterpart, a bare frame, were prefabricated and tested under quasi-static loading. Effect of the cladding panel and the proposed connections on the seismic performance of the steel frame was evaluated. It was indicated that the damage of the tapered connector was caused by the rupture of one energy dissipation plate during the fatigue loading and the hysteresis behavior of the connector was affected by the membrane effect. The proposed energy dissipation connector can improve the strength, stiffness, especially the energy dissipation capacity of the subassembly. However, the failure of both subassemblies was mainly caused by the yielding of the column foot and buckling of the beam end, therefore the cladding panel did not change the damage pattern of the steel frame. Three-dimensional (3D) finite element (FE) analysis was conducted to reproduce the tests of the connectors and the subassemblies, facilitating a better understanding of the working mechanism of the system.

Pull-down test and numerical validation of multi-story steel moment frame using pulley-based loading system

Regarding the structural robustness against progressive collapse, recent studies have revealed that the catenary effect is the critical resisting mechanism for the frame structures under large vertical displacement. The previous studies of the single floor beam-column subassemblies suggest that the catenary effect is greatly affected by the connection performance as well as the horizontal restraint. However, the conventional push-down testing might not appropriately represent the horizontal constraint from the surrounding bays and the vertical loading condition under the uniformly distributed gravity loads. Therefore, the static pull-down test is performed on the multi-story steel moment frame equipped with straight-reduced-section splice plates (SRSP). It is used for high deformability of beam-to-column connection. In addition, a vertical loading system using the fixed pulleys for load transferring is newly proposed for a feasible and safe loading procedure. The experimental results show that the growth of vertical resistance can be mainly attributed to the plastic hardening and the consecutive catenary effect. The maximum resistance is governed by the first rupture of SRSP at the overall chord rotation of 0.178 rad, indicating high deformability of bolted connection with SRSP. Based on the failure sequence of connections and the internal force as well as deformation response, the floor dependency of catenary effect can be significantly observed. It is characterized by the earliest failure emerging at the 1st floor, followed by the consecutive ruptures observed at the upper floors. In terms of the internal force, the vertical contribution derived from the tensile force will be gradually rising for the connection at the 1st floor, in contrast to the negligible catenary effect at the 2nd and 3rd floors. Eventually, the numerical simulation is performed based on the previously proposed material model. The simulated full-range force-displacement curve with the low percentage error of 0.8% for the first rupture displacement demonstrates the validity of the numerical model in terms of the full-range behaviors of multi-story frame structure.

Collapse resistance of multi-storey steel frame structures: Evaluation method based on member resistance

As the interaction of structural members and the type of beam-to-column connections significantly influence the collapse resistance of steel frame structures, there are limitations in using the existing theoretical models to calculate the resistance of multi-story steel frame structures with different structural parameters. The collapse resistance of multi-storey frame structures can be calculated using member resistance based on determining the inter-story constraints and the law of mutual influence of inter-story internal forces. In this paper, the resistance of structural members during the small and large deformation stage is discussed based on the coupling relationship between the bending moment and axial force developed in members. The theoretical analysis showed that the evolution of internal force multi-storey frames was reflected in the inter-story differences of flexural resistance and axial forces in the small and large deformation stages, respectively. Thus, a resistance calculation method suitable for steel frame structures with different connections was proposed based on member resistance. Finally, the rationality of the theoretical method was verified through a multi-scale model. The theoretical calculations showed a significant agreement with the numerical results.

Study on Numerical Simulation of Seismic Collapse of RC Frame Structure with Infilled Wall

The infilled wall plays an important role in the formation of the survival space and life‐saving passage of the seismic collapse of reinforcement concrete (RC) frame structure. Here, with the numerical modeling method of the infilled wall, the connection between infilled wall and RC frame was primarily investigated. The combined finite element (FE) and finite‐discrete element (F‐DE) method is proposed to simulate the multispan and multistory RC frame structure with infilled wall. The reliability of the numerical simulation method was verified by the shaking table test; the evaluation criterion includes the collapse mechanism and mode. The results show that the numerical simulation is highly consistent with the shaking table test; it is easy for RC frame structure to form short columns due to the influence of the low or half‐height infilled wall, and the structural collapse is caused by the shear failure of columns; the overall structure shows pancake type of collapse; the survival space becomes smaller and smaller on the direction of structural collapse. The proposed numerical simulation method can be valuable in simulating RC frame structure with infilled wall for postearthquake rescue.

Probabilistic seismic assessment of the pounding risk based on the local demands of a multistory RC frame structure

The aim of this study is to incorporate the local inelastic demands of a multistory reinforced concrete (RC) frame structure for the first time in the probabilistic seismic assessment of the pounding risk. Two distinct types of structural pounding are examined: a) the floor-to-floor structural pounding - Type A, and b) the inter-story (floor-to-column) structural pounding - Type B. Three different initial gap distances dg between the adjacent structures are considered. The seismic performance of the RC frame structure without the pounding effect is also estimated. The probabilistic evaluation of the pounding effect is performed through fragility curves in terms of global and local engineering demand parameters (EDPs) as a function of the peak ground acceleration (PGA). The first part of this research is focused on the development of global and local probabilistic seismic demand models (PSDMs) against pounding risk. For this purpose, linear and bilinear regression models have been used. Afterwards, the fragility assessment of the RC frame against pounding is performed (a) as a function of the separation gap distance dg, (b) based on the global seismic performances, and (c) based on the local seismic performances. A compounded fragility-based solution on evaluating the pounding risk at different performance levels is also presented and new performance levels thresholds are introduced. Results indicate that the local performances of the columns of the RC structure are crucial demand parameters for the probabilistic assessment of the pounding risk. The type of the structural pounding (Type A or Type B) that is occurred between the adjacent structures significantly alters the results of the probabilistic assessment when the local performances are considered. The compounded evaluation of the pounding risk clearly indicates that the RC frame structure exceeds the examined performance levels at a lower value of PGA when subjected to pounding in comparison to the corresponding cases without pounding. Finally, a decision method is presented as an approach to estimate the minimum separation gap distance dg,min between adjacent structures when global and local performances are incorporated in the fragility assessment process.

Identification and semi-active control of structures with abrupt stiffness degradations

This paper presents for variable stiffness tuned mass dampers (VS-TMDs) a vibration control algorithm combined with a nonlinear system identification method. The objective of the proposed approach is the control of multistory shear frame structures, which exhibit abrupt stiffness degradations. A stiffness variable control (SVC) algorithm is developed to control the stiffness of the VS-TMD, which is based on the mitigation of the potential energy of the structure. For the identification of the system parameters, an adaptive unscented Kalman filter (A-UKF) scheme is utilized. The paper describes the theoretical background of the proposed approach with its governing equations and conducts performance studies on a semi-actively controlled 2-story shear frame structure. Harmonic, white noise and earthquake excitation scenarios including seismic aftershock effects are investigated. Sensitivity studies are conducted. With the proposed approach, the abrupt stiffness changes of the structure are detected and the damper stiffness is adapted successfully. The results show that the SVC together with the A-UKF clearly outperforms the passive TMD control.

Behaviour of RC beam-column joint with varying location ofconstruction joints in the column

According to ACI 224.3R-95 (ACI, 2013), construction joints (cold joint) in the column are to be provided at the top of floor slab for column continuing to the next floor and underside of floor slab and beam. A recent study reveals that providing cold joint of the mentioned location significantly reduced the seismic performance of the frame structures. Since, the construction joints in multi-story frame structures normally provided at the top of the floor slabs and at soffit of the beam in the column. This study investigated the effect of construction joint at various location in the column of beam-column joint such as at the top of floor slab, soffit level of the beam, half the depth of beam below the soffit of the beam and at a full depth of the beam below the soffit of the beam. The study revealed that there is an improvement in seismic capacity of the specimens as the location of cold joint is placed away from the soffit of the beam for lower story column.

Strain rate dependent formulation of the latent heat evolution of superelastic shape memory alloy wires incorporated in multistory frame structures

Due to their unique hysteretic energy dissipation capacity, shape memory alloy (SMA) wires are particularly interesting for the development of new-type of intelligent vibration control systems for structures. However, in structural control, most of the vibrations occur in high strain rate regimes, which interfere the release of self-generated heat and thus influence the hysteretic dissipation. This paper proposes a strain rate dependent formulation of the latent heat evolution and aims to improve the accuracy of existing macroscopic modeling approaches developed for SMA wires particularly for the dynamic load cases. The proposed formulation is determined phenomenologically and implemented in a continuum thermomechanical framework based constitutive SMA wire model without impairing the simplicity and robustness of the solution process. The proposed formulation is validated by cyclic tensile tests conducted on SMA wires. Results show that the calculations using the formulation can predict the wire response more accurately than the strain rate independent formulation. For the simulation of multistory frame structures incorporating multiple SMA wires, the governing equations are driven. Shaking table tests are conducted on a 3-story frame structure under harmonic and seismic excitation. The responses of the structure are successfully replicated using the strain rate dependent latent heat formulation.