Y.B. Yang

Verified

Y.B. verified their affiliation via an institutional email.

Learn more

Verified

Y.B. verified their affiliation via an institutional email.

Learn more

• Ph.D.
• Professor at Chongqing University

Measuring the bridge frequencies indirectly from a test vehicle passing the bridge is featured by its mobility, economy and promptness, compared with the conventional technique that requires vibration sensors to be mounted directly on the bridge. However, the road surface roughness may pollute the vehicle spectrum, rendering the bridge frequencies...

The variation of the instantaneous frequencies of bridges under moving vehicles is a problem not well studied in the literature. A theoretical framework is presented for the problem, considering the variation in frequencies for both the bridge and moving vehicle. First, the equations of motion are written for the two sub-systems. By solving the eig...

Measuring the bridge frequencies indirectly from a test vehicle is a potentially powerful technique for its advantage of efficiency and economy. However, the existence of road surface roughness may excite the vehicle-related frequencies to a higher level of amplitude than the bridge-related ones, making it difficult to identify the bridge frequenci...

By letting a test vehicle move over a bridge, the frequencies of the bridge can be identified by picking the peaks in the Fourier response spectra of the test vehicle. One problem with this approach is that the vehicle frequency (undesired) usually appears as a dominant peak in the spectrum, making it difficult to identify the bridge frequencies (d...

The Hilbert–Huang transform (HHT) proposed for treating the time history data of nonlinear dynamic systems comprises two parts: the empirical mode decomposition and the Hilbert transform. In this study, focus is placed on the physical interpretation of the HHT results for an elastic two-member truss, for which the nonlinear behaviour can be clearly...

This paper is aimed at formulating a highly efficient pretwisted beam element for the buckling analysis of linearly pretwisted columns under various end loads. First, a torsional (or convected) coordinate system for the pretwisted beam of rectangular cross-sections is defined, in addition to the fixed coordinate system. Based on the updated Lagrang...

This paper uncovers the frequency variation in plate-type bridges under moving vehicles, highlighting the transverse characteristics stemming from the bridge’s spatial configuration. First, the mode shapes are determined for plates with two opposite sides simply supported and the other two free (S-F-S-F bridge) by Levy’s method. Then, analytical so...

The vehicle scanning method (VSM), originally known as the indirect method, is an efficient method for bridge health monitoring that utilizes mainly the responses collected by the moving test vehicles. This method offers the advantage of mobility, efficiency, and cost-effectiveness as it requires only one or a few vibration sensors mounted on the t...

Previously, classical boundary conditions (i.e. simple, fixed and cantilevered) have been adopted for the beams under the moving loads in deriving the dynamic response. In reality, most beams cannot be simply classified as the ones with classical supports, but are elastically restrained. For theoretical completeness, a general theory will be develo...

This paper investigates the use of straight-beam elements to simulate the vibration of curved beams that is mathematically more challenging. First, analytical solutions of the out-of-plane and in-plane dynamic responses of the curved beam are derived for reference. Then, for the straight beam approach, the elastic stiffness matrix, consistent mass...

With the three dimensional (3D) oblique incident waves exactly determined for the free field, the soil seismic responses in both frequency and time domains are studied by the 2.5 dimension (2.5D) finite/infinite element method. First, the free-field responses in frequency domain are solved exactly for 3D arbitrary incident P and SV waves, which req...

This paper investigates comprehensively the resonance and cancellation conditions for the free vibration of elastically-supported (ES) beams subjected to successive moving loads. Focus is placed on application of the cancellation condition to minimize bridge vibrations, considering particularly the effect of elastic supports. In terms of the modal...

This article aims to theoretically analyze the influence mechanism of boundary support conditions and their variations on the dynamic characteristics of bridges, as well as the conditions for resonance and cancellation. The article first proposes a simplified expression for the vibration mode of an elastic support beam considering unequal left and...

Continuous rails are often modeled as infinite beams. In this paper, closed-form solution is newly derived by the residue theorem and Green’s function for the dynamic response of an infinite beam resting on viscoelastic foundation under a harmonic moving load. The most suitable span length will be determined for the analogic finite beam (which can...

Angle cross-section members are widely used in various transmission towers owing to their convenient connections, easy availability, simple production processes, and high efficiency. Such members are very susceptible to nonlinear behavior when subjected to abnormal or extreme loads. In this work, a new geometric stiffness matrix for thin-walled ste...

Conventional beam elements ignoring distortion may overestimate the lateral resistance of frames and curved beams made of monosymmetric I-sections. This paper introduces two new distortional modes represented by mechanical couples relative to twisting and shearing of the two flanges that are opposite in directions but unequal in magnitudes. A strai...

In this paper, a simple formula is derived for the modal damping ratio of the bridge using the correlation between the instantaneous amplitudes of the related front and rear contact responses of a two-axle test vehicle by the Hilbert transform (HT). To start, closed-form solutions were derived for the dynamic response of the damped bridge and vehic...

The advent of railways and especially highspeed railways marks great strides in human transportation history. To guarantee exclusive right-of-way, highspeed railways are often built on equal simply supported beams resting on piers. In this paper, a historical review will be given of the resonance and cancellation phenomena observed for simply suppo...

Keywords: Seabed seismic analysis Oblique incident seismic waves Equivalent seismic forces Finite/infinite element method Solid-liquid coupling A B S T R A C T The seabed seismic analysis of a viscoelastic half-space with overlying liquid under two-dimensional (2D) oblique incident P-or SV-waves is performed by the finite/infinite element method (F...

Wavelet transform (WT) is theoretically studied to recover the bridge mode shapes from a passing two-axle test vehicle by using the correlation between the front and rear contact points. In this paper, closed-form solution is derived for the dynamic response of the bridge. To avoid the masking effect brought by vehicle's natural frequencies on brid...

A hybrid time–frequency method is proposed for accurately estimating the modal parameters of bridges, including the closely spaced modes, by a single-axle scanning vehicle fitted with multi sensors. The novelty of the method is the combined use of the wavelet transform (WT) and singular value decomposition (SVD) for processing the cross covariances...

Dual-function amplifiers are proposed for the first time herein for enhancing the capability of a scanning test vehicle for bridges. To start, closed-form solutions are derived for the dynamic responses of the amplifier-vehicle-bridge system with a moving test vehicle. Then, the dynamic amplification factors of the amplifier and vehicle are present...

This paper scans for the first time the vertical and radial (lateral) frequencies of a horizontal curved beam from the respective motions of a single-axle test vehicle by a theoretical approach. The vehicle is innovatively treated as a system with two orthogonal degrees of freedom (DOFs), each of a spring-dashpot unit, to capture both the vertical...

In this paper, the internal and external cancellation phenomena for damped beams subjected to multi-moving loads are investigated in detail. To start, the theory for the vibration of a simply supported beam is revisited by including the effect of damping. For the first time, a simple expression is derived for the free vibration of the damped beam u...

The contribution of this paper is to recover the vertical and radial mode shapes of curved bridges from the contact responses of a single-axle scanning vehicle using the variational mode decomposition (VMD) and synchrosqueezed wavelet transform (SWT) for the first time. To catch both the vertical and radial vibrations of the curved bridge, the test...

The two support bearings of an elastically supported (ES) bridge may be unequal in stiffness due to aging or other factors. This paper proposed an effective technique of using the contact residual response (CRR) generated by a two-axle test vehicle in its round-trip movement to detect the weak end and frequencies of the bridge. First, the round-tri...

The seismic analysis of a viscoelastic half-space under two-dimensional (2D) oblique incident waves is carried out by the finite/infinite element method (FIEM). First, the frequency-domain exact solutions for the displacements and stresses of the free field are derived in general form for arbitrary incident P and SV waves. With the present formulat...

An effective procedure is proposed for scanning and separating the vertical (flexural) and torsional–flexural frequencies of thin-walled girder bridges by a moving single-axle test vehicle, modeled as a two degree-of-freedom (DOF) system to account for the vertical and rocking motions. The response of the vehicle is not directly used, since it may...

Vehicle’s wheels were mostly modeled as a point, which can touch the valleys of pavement roughness, creating unrealistic high-frequency oscillation. This can be avoided by using the disk model for the wheels, which however adds significant complexity to the vehicle–bridge interaction (VBI) analysis. In this paper, a refined roughness formula is gen...

A general formula for the contact response of a single-axle, two-mass test vehicle considering the suspension effect is derived herein for scanning the bridge frequencies, which can be used not only for the simple beams adopted in the derivation, but for other beam-type bridges. It was known that the bridge frequencies in the vehicle spectrum direc...

The response of a test vehicle moving over bridges may be worsened by vehicle’s self frequency and pavement roughness, since they both can pollute the vehicle spectrum for bridge frequency identification. This paper is aimed at tackling the above two factors using a novel software/hardware means, i.e., by using the vehicle-bridge contact response t...

For the first time, the single-axle-two-wheel test vehicle is used to detect the damage of a plate-type bridge that is simply supported at the two longitudinal ends, but free on the lateral sides. The test vehicle with two wheels is refined as a two degree-of-freedom (DOF) system to capture the motions in both the longitudinal and lateral direction...

Bearings are commonly inserted on bridge piers to mitigate the seismic forces transmitted upward. But they often become unequal in stiffness due to ageing, overloading, etc. This study made the first attempt to exploit the soft-end amplification (SEA) effect on scanning of frequencies of the bridges with unequal end bearings, using the novel techni...

The vehicle scanning method (VSM), an indirect approach for bridge measurement, has attracted intensive attention since it was proposed by Yang and co-workers in 2004. This method is featured by the fact that no vibration sensors need to be mounted on the bridge, but only one or few vibration sensors are required on the test vehicle. Such an idea h...

This paper proposes a furthering approach for extracting the first several flexural and torsional–flexural frequencies of thin-walled box girders from the residual contact response of a two-wheel test vehicle passing the bridge. Unlike most previous studies, the single-axle test vehicle is modeled as a two degree-of-freedom (DOF) system to account...

Vehicle frequency and pavement roughness are two factors that used to adversely affect the vehicle scanning method for bridges. To tackle these at once, this study proposes the use of a novel frequency-free test vehicle in parked state for bridge measurement. In terms of measurement speed and data quality, the proposed technique is a trade-off betw...

Frequent resonance may result in excessive vibrations and endanger the safety of bridges. Firstly, the governing equations of motion are derived for the vertical, lateral and torsional vibrations of a mono-symmetric thin-walled box beam under a harmonic moving load. Then the resonance conditions are derived by letting the denominator of the respons...

A theoretical framework is presented for detecting the damages in the constituents of track-bridge systems from the vehicle-rail contact response. The rail and bridge are modeled as dual beams interwoven by a viscoelastic layer to account for track fasteners, sleepers and ballast. The single-axle test vehicle is modeled as a single degree-of-freedo...

The scanning of bridge surface roughness by the test vehicle is a coupled and non-stationary problem since the bridge deflection caused by vehicles will inevitably enter into the vehicle response. To this end, a two-step procedure is proposed to retrieve the bridge surface profile from the noise-contaminated responses of a two-axle vehicle moving o...

The straight-beam approach is a simple and efficient means for analyzing the buckling of curved beams. Although previous researchers showed that the straight-beam approach is capable of simulating the lateral buckling of solid curved beams, the warping effect had been neglected and thus its practical application in engineering was limited. In this...

Steel moment frames supported on two different ground levels have been widely constructed in the mountainous high-seismicity regions of China. To investigate the seismic collapse behavior of such frames, 3D numerical analysis models were established in Perform-3D and verified to simulate the collapse process. Different structural configurations wer...

Both vehicle frequencies and road roughness are factors that may render the vehicle scanning method ineffective for bridges. In this paper, both factors will be eliminated via the skillful use of a two‐axle test vehicle. Namely, the effect of vehicle frequencies is removed by using the vehicle–bridge contact (point) responses and road roughness by...

This paper removes the subjective judgment by proposing a technique for automatically identifying the bridge frequencies using singularity spectrum analysis and K-means clustering. First, the vehicle-bridge contact-point acceleration newly derived from is used to avoid the adverse effect brought by vehicle’s frequency. Next, the contact signal is p...

A self-designed single-axle vehicle is used to detect the bridge frequencies from its rocking motion, caused by wheels moving over an uneven surface. To include both the rocking and vertical motions, the single-axle vehicle is modeled as a two degree-of-freedom (DOF) system, unlike the previous single-DOF model. The rocking frequency, an inborn pro...

The overhead catenary system is a crucial conductor for delivering steady electric power to the trains running on modern electrified railways. The propagation of vibration waves in the catenary system is of interest to railway engineers due to the pantograph-catenary interaction. To explore the wave transmission via the contact wires of a catenary...

The 2.5D approach is an efficient tool for the dynamic analysis of half-space with longitudinally invariant properties. In this paper, a newly formulated 2.5D version of the NURBS-based isogeometric analysis (IGA) and the scaled boundary IGA (SBIGA) is proposed for analyzing the bounded and unbounded domains, respectively, of a soil-tunnel system s...

p>Impact factors that are more rational for bridges were proposed in 1995 using the vehicle-bridge interaction (VBI) element derived, by which the term VBI first appeared. Resonance and cancellation conditions were proposed for highspeed (HS) railway bridges, by which the optimal span length L was proposed to be 1.5 times the carriage length. Based...

This paper studies theoretically the retrieval of torsional-flexural frequencies of mono-symmetric thin-walled box girder bridges from vehicles’ residual contact response for the first time. To start, the three-dimensional vehicle–bridgeequations of motion including the lateral and torsional (coupled) and vertical (uncoupled) vibrations are derived...

In this paper, by implanting the rigid body rule (RBR)-based strategy for static nonlinear problems into the implicit direct integration procedure, an efficient and robustness nonlinear dynamic analysis method for the response of framed structures with large deflections and rotations is proposed. The implicit integration method proposed by Newmark...

A theory is presented for retrieving the track/bridge frequencies and track modulus from an instrumented vehicle moving over a dual-beam model to simulate the track-bridge system. The dual beams are connected by uniform spring-dashpot units to simulate the effects of sleepers and ballast, etc. Based on the dual-beam model, the response of the vehic...

The hybrid coupled wall (HCW) system consists of steel coupling beams that connect adjacent reinforced concrete (RC) wall piers. In order to minimize or even eliminate the lengthy design iterations of conventional performance-based seismic design method and directly account for inelastic structural behavior, the modified energy-balance based plasti...

Two factors are critical to the effectiveness of the vehicle scanning method for bridge frequencies. One is the frequency of the test vehicle itself. This can be eliminated by using the vehicle–bridge contact point response calculated from the vehicle response. The other is the surface roughness of the bridge, which can be removed by using the resi...

By the vehicle scanning method, an instrumented test vehicle is used to scan the frequencies of vibration of the underlying bridge. In this paper, a realistic theory is proposed considering the damping effect of the test vehicle, which was not well studied previously. Bridge damping is ignored since the bridge vibration sensed by the moving vehicle...

For a train moving along a curved path, centrifugal forces are induced in addition to gravitational loads. In this paper, the 2.5D approach for loads moving along a straight path is extended to treating both the vertical and horizontal loads moving along a curved path. Firstly, closed-form solutions for the problem are derived for the cases of vert...

Bridge damping ratios are extracted via the skillful use of the single-degree-of-freedom (DOF) test vehicle for the first time in this paper. Central to the simultaneous retrieval of the first few frequencies and damping ratios from the contact (point) response of the bridge is the use of the variational mode decomposition (VMD) and random-decremen...

This paper presents an invariant isogeometric formulation for the geometric stiffness matrix of spatial curved Kirchhoff rods considering various end moments, i.e., the internal (member) moments and applied (conservative) moments. There are two levels of rigid-body qualification, one is on the buckling theory of the rod itself and the other on the...

There are large number of small- and medium-span bridges with a wide distribution. Their low maintenance investment makes the development of a rapid, economical, and accurate technique for assessing their condition and verifying their safety a key problem to be solved in infrastructure management. In 2004, Yang et al. proposed an indirect measureme...

The 2.5D dynamic response of a half-space to an internal point load moving at sub- and super-critical speeds is studied in Cartesian coordinates both analytically and numerically. Firstly, the partial differential equations of waves are converted to the ordinary differential equations by the Fourier transformation. Then, a multiplying factor is der...

This study establishes a short-time stochastic subspace identification (ST-SSI) framework to estimate bridge frequencies by processing the dynamic response of a traversing vehicle. The formulation uses a dimensionless description of the response that simplifies the vehicle-bridge interaction (VBI) problem and brings forward the minimum number of pa...

This study presents an effective procedure for extracting the first few bridge frequencies using the data collected by a moving test vehicle. Previously, the effectiveness of the vehicle scanning method for bridge frequencies was hampered by factors such as vehicle frequency and road surface roughness. To this end, the contact-point response of the...

A vibration amplifier is first proposed for adding to a test vehicle to enhance its capability to detect frequencies of the bridge under scanning. The test vehicle adopted is of single-axle and modeled as a single degree-of-freedom (DOF) system, which was proved to be successful in previous studies. The amplifier is also modeled as a single-DOF sys...

This article reports the development of a methodology for detecting ballast damage under a sleeper based on measured sleeper vibration following the Bayesian statistical system identification framework. To ensure the methodology is applicable under large amplitude vibration of the sleeper (e.g. under trainload), the nonlinear stress–strain behavior...

In this study, a new, effective procedure is proposed for identifying the surface roughness from the responses recorded of two connected test vehicles moving over the bridge. Central to this study is the proposal of a simple static correlation formula for relating the dynamic deflections of the two vehicles’s contact points on the bridge, via the d...

The pantograph-catenary system is essential to the operation of modern railways. The overhead catenary system serves to deliver steady electric power to the trains running on the railways. The propagation of waves in the catenary system can be significantly affected by its interaction with the pantograph. To investigate the wave transmission via th...

For damage detection of railway tracks, a two-axle test vehicle is better than a single-axle vehicle due to its capability of self standing and stability. This paper presents a new, comprehensive theoretical framework for a two-axle test vehicle moving over railway tracks modeled as a simply supported beam with elastic foundation. Firstly, closed-f...

The vehicle scanning method (VSM), an indirect approach for bridge measurement, has attracted intensive attention since it was proposed. By this method, a moving test vehicle is employed to detect the “mechanical” properties of the bridge, e.g. frequencies, mode shapes, damages, etc., utilizing the interaction between the two substructures. Compare...

Lateral buckling of cantilevered circular arches under various end moments is studied using an analytical approach. Three types of conservative moments are considered, i.e. the quasi-tangential moments of the 1st and 2nd kinds, and the semi-tangential moment. The induced moments associated with each of the moment mechanisms undergoing three-dimensi...

An effective technique is proposed for identifying the track modulus, i.e., the foundation stiffness of the rails, using the contact-point response of the moving test vehicle. First, for a simple beam resting on an elastic foundation under a moving sprung mass, closed-form solutions are derived for the responses of the vehicle and its contact point...

Nonlinear analysis of structures is an effective way for predicting the bearing capacity or ultimate strength of a structure. This paper will review researches on the nonlinear, buckling, postbuckling and elasto-plastic analyses of three-dimensional (3D) framed structures. Also considered are curved beams since they share the problem of joint equil...

In the isogeometric formulation for three-dimensional Kirchhoff rods, the invariance is required such that rigid-body modes associated with translations and infinitesimal rotations can be exactly represented. By enforcing the invariance in the isogeometric formulation of the rod, the equilibrium of forces and moments at fixed ends is preserved, and...

Based on the continuum mechanics principles, a rigorous formulation is presented for the linearized stiffness equation of three-dimensional beam elements with account taken of the joint moment equilibrium in the deformed configuration C2. By sticking to the Bernoulli–Euler hypothesis of plane sections and elasticity definitions for stress resultant...