Naiwei Lu

• PhD
• Professor (Associate) at Changsha University of Science and Technology

The deflection control of the main girder in suspension bridges, as flexible structures, is critically important during their operation. To predict the vertical deflection of existing suspension bridge girders under the combined effects of stochastic traffic loads and environmental temperature, this paper proposes an integrated deflection interval...

The rib-to-deck (RD) welded connections are one of typical fatigue-prone details in early aging orthotropic steel decks (OSDs), which pose a potential threat to the structural behavior and safe operation of steel bridges. This study investigates the propagation characteristics and coupling effects of penetrating cracks in OSD. A large-scale OSD spe...

Identifying structural damage is an essential task for ensuring the safety and functionality of civil, mechanical, and aerospace structures. In this study, the structural damage identification scheme is formulated as an optimization problem, and a new meta-heuristic optimization algorithm, called visible particle series search (VPSS), is proposed t...

In order to improve the stiffness and shear bearing capacity of steel-UHPC composite bridge, an innovative shear connector named arc-shaped reinforcement shear connector was proposed and compared with the stud and perforated bar steel plate shear connector using the static push-out test. Considering shear connector diameter, a total of ten push-out...

The steadily growing traffic load has resulted in lots of bridge collapse events over the past decades, especially for short-to-medium span bridges. This study investigated probabilistic and dynamic traffic load effects on short-to-medium span bridges using practical heavy traffic data in China. Mathematical formulations for traffic-bridge coupled...

This paper systematically performed fatigue crack propagation (FCP) tests to investigate the corrosion fatigue crack propagation (CFCP) behavior of HRB400 steel bar. The fatigue loading scheme involved the constant amplitude loading and stepwise decreasing amplitude loading. The load ratio, the ratio of the minimum load to the maximum load, was des...

A cable-supported bridge is usually a key junction of a highway or a railway that demands a higher safety margin, especially when it is subjected to harsh environmental and complex loading conditions. In comparison to short-span girder bridges, long-span flexible structures have unique characteristics that increase the complexity of the structural...

Innovative double-sided welding is expected to improve the fatigue resistance of rib-to-deck welded joints of orthotropic steel decks (OSDs). Welding crack-like defects are the crucial issue affecting the fatigue performance of rib-to-deck double-sided welded joints. This study presents a numerical simulation of three-dimensional (3D) mixed mode fa...

The current volume of freight traffic has increased significantly during the past decades, impacted by the fast development of the national transportation market. As a result, the phenomena of truck overloading and traffic congestion emerge, which have resulted in numerous bridge collapse events or damage due to truck overloading. Thus, it is an ur...

The traffic load has grown significantly in recent years, which might be a threat for the service safety of existing bridges. Thus, it is an urgent task to assess the actual traffic load effects on bridges, considering actual heavy traffic load instead of design traffic load. This study presents a framework for extrapolating maximum dynamic traffic...

The fast-growing traffic loads may become a safety hazard for existing bridges especially in developing countries. One of the problems induced by heavy traffic loads is the fatigue damage accumulation of the welded joints in steel bridge decks. This study utilized a stochastic traffic flow model and a novel computational framework for estimating fa...

The cables in a cable-stayed bridge are critical components supporting the long-span girders and ensuring their functionality. However, cables are prone to fatigue damage and atmospheric corrosion, which directly affect the bridge safety. This study presents a framework for system reliability evaluation of in-service cable-stayed bridges subjected...

This study presents a novel approach to simulating the fatigue stress spectra of short- to medium-span bridges under stochastic and dynamic traffic loads. The stochastic traffic load is simulated based on the weigh-in-motion (WIM) measurements of a heavy-duty highway bridge in China, and the dynamic effects are modeled using a vehicle-bridge couple...

Steady traffic growth may pose a safety hazard to in-service bridges, especially long-span bridges subjected to the simultaneous presence of multiple heavy-duty trucks. This study presents a methodology for evaluating the statistical extrapolation of traffic-load effects on long-span bridges. As part of the contributions advancing the state of the...

Long-span bridges suffer from higher traffic loads and the simultaneous presence of multiple vehicles, which in conjunction with the steady traffic growth may pose an threat to the bridge safety. A steady traffic growth may pose a safety hazard to in-service bridges, especially for long-span bridges under the event of simultaneous presence of heavy...

The inherent variability of major infrastructure can be associated with structural properties such as member size and geometry, elastic constants, density, strength characteristics or external load types. These variables and factors may give rise to risk, safety and uncertainty for general structures. In this paper, a comprehensive reliability eval...

Bridges are vulnerable to the fatigue damage accumulation caused by traffic loading over the service period. A continuous growth in both the vehicle weight and the traffic volume may cause a safety hazard to existing bridges. This study presented a computational framework for probabilistic modeling of the fatigue damage accumulation of short to med...

Long-span bridges suffer from higher traffic loads and the simultaneous presence of multiple vehicles, which in conjunction with the steady traffic growth may pose a threat to the bridge safety. This study presents a methodology for first-passage probability evaluation of long-span bridges subject to stochastic heavy traffic loading. Initially, the...

A new fatigue reliability assessment function which takes into account the vehicle and temperature loadings has been developed in this study. The vehicle and temperature loadings are important parameters as they can cause fatigue failure of the welds in a steel box girder. The temperature affects the traffic loading effect by changing the elastic m...

A steady traffic growth has posed a threat to the fatigue safety of existing bridges. Uncertainties in traffic flows add to the challenge of an accurate fatigue safety assessment. This article utilizes a stochastic traffic load model to evaluate the fatigue reliability of orthotropic steel bridge decks. The traffic load model is simulated by site-s...

In order to analyze the probabilistic characteristics of dynamic responses and safety level of stiffening girders for long-span suspension bridges considering the actual vehicle states, the vehicle involving vibration and the dynamic reliability indices were studied based on the measured vehicle data and dynamic reliability theory. The mathematic m...

Welded joints in steel bridge decks are vulnerable to the fatigue damage caused by heavy-loaded trucks. A realistic probabilistic model of truck loads provides a basis for simulating the fatigue stress spectrum of these welded joints, where the fatigue reliability assessment can subsequently be carried out. In this paper, a stochastic fatigue truck...

Engineering structures are most statically indeterminate structures consisting of various types of components and their failure modes exhibit randomness under random loads. A new adaptive support vector regression method is proposed for structural system reliability assessment. Compared with traditional support vector regression, the proposed adapt...

To study the vehicle traveling parameter characteristics and vehicle load action effect under the actual vehicle operation, the probability models that were compatible with the parameters of the traveling speeds, spacing and axle weight of the vehicles on Yibin-Luzhou Expressway were established, based on the weigh-in-motion (WIM) test data of the...

Two updating processes of support vectors were introduced into the traditional support vector regression (SVR) method for the purpose of presenting a new adaptive support vector regression (ASVR) method, in order to solve the key issues of structural system reliability assessment. Importance sampling Monte-Carlo simulation (MCS) was used to estimat...

A new system reliability assessment method is proposed based on updating support vector method, considering the characteristic of cable -stayed bridges with explicit performance functions and multiple failure modes. The traditional Support Vector Machine (SVM) is developed and applied to system reliability analysis of cable -stayed bridges. There a...

Most research studies on structural optimum design have focused on single-objective optimization of deterministic structures, while little study has been carried out to address multi-objective optimization of random structures. Statistical parameters and redundancy allocation problems should be considered in structural optimization. In order to add...

Abstract: Optimum structures must have adequate resistance against external random loads. Since most truss structures involve a series of failure processes, it is necessary to develop system reliability analyses for the optimum design of truss structures. In this paper, a hybrid method of system reliability-based design optimisation (SRBDO) is prop...

The temperature distribution of high piers with concrete-filled steel tubes (CFST) is investigated by continuously observing the temperature distribution of Labajin Bridge in Ya’an-Lugu expressway. Mathematical statistical methods are used to study the temperature gradient of the cooling mode. Results show that the closer the distance between the m...