Probabilistic numerical evaluation of dynamic load allowance factors in steel modular bridges using a vehicle-bridge interaction model

Alencar

2023

Metals

Fatigue cracking is one of the most prominent causes of mechanical failure limiting the service life of existing steel and composite steel–concrete bridges and is among the central concerns of structural and bridge engineers. In this context, the current work presents some recent advancements in an existing methodology for fatigue analysis developed by the authors throughout the years. The methodology is specifically devoted to the fatigue assessment of composite steel–concrete bridges employing the local hot-spot S-N approach and a coupled vehicle–pavement–bridge system considering progressive pavement deterioration with stochastically generated roughness profiles. Two different methodologies were used to solve the dynamic equilibrium equations: the modal superposition method to solve the bridge dynamic equations and a direct integration method to solve the vehicle dynamic equations. From a computational point of view, the present approach is more efficient and detailed than previous versions, as it allows a significant reduction in the analysis time and the use of complex bridge and vehicle finite element models. In this regard, a case study of a highway composite steel–concrete bridge spanning 40 m was selected in order to demonstrate the usefulness of the presented improved methodology by carrying out a fatigue analysis. The results of this investigation (displacements and stresses) are presented, aiming to verify the factors that directly influence the structural response and, consequently, the service life of steel–concrete composite highway bridges.

Section: Hl-93 Vehiclementioning

confidence: 99%

Advances in Methodology for Fatigue Assessment of Composite Steel–Concrete Highway Bridges Based on the Vehicle–Bridge Dynamic Interaction and Pavement Deterioration Model

Alencar

2023

Metals

Int. j. adv. appl. sci.

“…In addition, the vehicle is simplified as three sprung masses, which represent the design truck HL93 defined in AASHTO (2012) with three axles spaced 4.3 m and with axle loads of 35.6 kN and 142.3 kN in the front and the other two, respectively. Table 3 presents the mechanical properties of the sprung-mass models, namely the mass, damping, and stiffness collected from Montenegro et al (2021) and Hu et al (2020).…”

Section: Parametric Analysismentioning

confidence: 99%

Incorporating the effect of approach slab to the dynamic response of simply supported bridges under moving vehicle

al.¹

2022

Reinforced concrete approach slabs serve as a transitional component between the roadway pavement and the bridge deck. Due to the settlement of the embankment soil, the slab is bent, and its slope grade will be suddenly changed resulting in bumps at both ends of the deck; this may increase the dynamic response of bridges induced by the interaction with moving vehicles. In addition, the presence of such bumps not only causes an uncomfortable ride but also exhibits a potentially hazardous condition to the traffic. Since most of the studies have considered either the interaction model between the slab and soil or between the bridge and moving load; in this study, a novel finite element model is established for the bridge under traffic loads, considering the presence of the approach slab that is simulated as a beam rested on a dynamic soil model. The separated models of the approach slab and bridge deck are validated by previous studies and demonstrate their accuracy in predicting the dynamic response of the bridge-vehicle system. A comprehensive parametric study is then performed considering the effect of the soil stiffness, the stiffness of the shear layer of the foundation, and the approach slab length. The results of the study are useful criteria for the practice design of the approach slab in different embankment conditions.

“…While the first method is restricted to the analysis of the structural response, since the vehicle is represented as a set of moving loads corresponding to its static axle loads, the latter can also be used to assess the vehicle's behavior, including its dynamic response and the contact forces that arise from the contact interface. These models can be used in both roadway [8][9][10] and railway [4][5][6][7] applications, with differences in the contact interface, namely, between tire-surface and wheel-rail contact mechanisms. Since the present work focuses only on railway, only the latter will be addressed hereinafter.…”

Section: Introductionmentioning

confidence: 99%

Wheel–rail contact model for railway vehicle–structure interaction applications: development and validation

Montenegro

Calçada

2023

Rail. Eng. Science

Self Cite

An enhancement in the wheel–rail contact model used in a nonlinear vehicle–structure interaction (VSI) methodology for railway applications is presented, in which the detection of the contact points between wheel and rail in the concave region of the thread–flange transition is implemented in a simplified way. After presenting the enhanced formulation, the model is validated with two numerical applications (namely, the Manchester Benchmarks and a hunting stability problem of a suspended wheelset), and one experimental test performed in a test rig from the Railway Technical Research Institute (RTRI) in Japan. Given its finite element (FE) nature, and contrary to most of the vehicle multibody dynamic commercial software that cannot account for the infrastructure flexibility, the proposed VSI model can be easily used in the study of train–bridge systems with any degree of complexity. The validation presented in this work proves the accuracy of the proposed model, making it a suitable tool for dealing with different railway dynamic applications, such as the study of bridge dynamics, train running safety under different scenarios (namely, earthquakes and crosswinds, among others), and passenger riding comfort.