Live-Load Girder Distribution Factors for Bridges Subjected to Wide Trucks

2000 ◽  
Vol 1696 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Sami W. Tabsh ◽  
Muna Tabatabai
Keyword(s):  
Finite Element ◽  
The United States ◽  
Live Load ◽  
Wheel Load ◽  
Element Analysis ◽  
Load Effect ◽  
Design Specifications ◽  
Girder Bridges ◽  
Girder Distribution Factors ◽  
Modification Factor

An important problem facing engineers and officials in the United States is the constraint imposed on transportation due to limitations of bridges. These limitations typically constrain vehicles to minimum heights and widths, to minimum and maximum lengths, and to a maximum allowable weight. However, with current demands of society and industry, there are times when a truck must carry a load that exceeds the size and weight of the legal limit. In this situation, the trucking company requests from the state departments of transportation an overload permit. For a truck with a wheel gauge larger than 1.8 m (6 ft), the process of issuing a permit for an overload truck requires a tremendous amount of engineering efforts. This is because the wheel load girder distribution factors (GDFs) in the design specifications cannot be used to estimate the live-load effect in the girders. In some cases, an expensive and time-consuming finite element analysis may be needed to check the safety of the structure. In this study, the finite element method is used to develop a modification factor for the GDF in AASHTO’s LRFD Bridge Design Specifications to account for oversized trucks with a wheel gauge larger than 1.8 m. To develop this factor, nine bridges were considered with various numbers of girders, span lengths, girder spacings, and deck slab thicknesses. The results indicated that use of the proposed modification factor with the GDF in the design specifications can help increase the allowable load on slab-on-girder bridges.

Buckling characteristics of cut-out borne composite stiffened hyperbolic paraboloid shell panel

2021 ◽  
pp. 146442072110058
Author(s):  
Sarmila Sahoo
Keyword(s):  
Finite Element ◽  
Orientation Angle ◽  
Buckling Load ◽  
Benchmark Problems ◽  
Hyperbolic Paraboloid ◽  
Element Analysis ◽  
Load Effect ◽  
Global Buckling ◽  
Fiber Orientation Angle ◽  
Shell Panel

The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.

Safe Platooning Headways on Girder Bridges

2021 ◽  
pp. 036119812110363
Author(s):  
Bowen Yang ◽  
Joshua S. Steelman ◽  
Jay A. Puckett ◽  
Daniel G. Linzell
Keyword(s):  
Prestressed Concrete ◽  
Limit State ◽  
Live Load ◽  
Load Effect ◽  
Operational Strategies ◽  
Reliability Indices ◽  
Girder Bridges ◽  
Legal Limits ◽  
Weigh In Motion ◽  
Load And Resistance Factor

Truck platooning—digitally linking two or more trucks to travel in a closely spaced convoy—is an emerging technology with the potential to save fuel and reduce labor. A framework is described to determine how much a platoon permit load might be increased above Federal Bridge Formula B legal limits, given strict control over the load characteristics and operational tactics. Soon, platoons are expected to advance not only with respect to traffic operations but also in their ability to weigh and report axle weight and spacing, functioning as mobile weigh-in-motion vehicles. Consequently, platoon live load statistics (bias and coefficient of variation) can differ from code assumptions, and are perhaps controllable, which poses a significant opportunity with respect to operational strategies. A parametric study is presented that examined safe headways between platooning trucks, considering different girder spacings, span lengths, numbers of spans, types of structure, truck configurations, numbers of trucks, and adjacent lane loading scenarios. The Strength I limit state was evaluated for steel and prestressed concrete I-girder bridges optimally designed using load and resistance factor design. Reliability indices, β, were calculated for each load case based on Monte Carlo simulation. Summary headway guidance was developed and is presented here to illustrate potential safe operational strategies for varying truck weights and platoon live load effect uncertainties.

Semi-discrete finite element analysis of slab–girder bridges

2002 ◽  
Vol 80 (23) ◽  
pp. 1789-1796 ◽  
Author(s):  
Mei-Wen Guo ◽  
Issam E. Harik ◽  
Wei-Xin Ren
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Girder Bridges ◽  
Discrete Finite Element

scholarly journals Spatial Finite Element Analysis for Dynamic Response of Curved Thin-Walled Box Girder Bridges

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yinhui Wang ◽  
Yidong Xu ◽  
Zheng Luo ◽  
Haijun Wu ◽  
Liangliang Yan
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Degrees Of Freedom ◽  
Response Analysis ◽  
Box Girder Bridges ◽  
Element Analysis ◽  
Box Girder ◽  
Girder Bridges ◽  
System A ◽  
Thin Walled

According to the flexural and torsional characteristics of curved thin-walled box girder with the effect of initial curvature, 7 basic displacements of curved box girder are determined. And then the strain-displacement calculation correlations were established. Under the curvilinear coordinate system, a three-noded curved girder finite element which has 7 degrees of freedom per node for the vibration characteristic and dynamic response analysis of curved box girder is constructed. The shape functions are used as the interpolation functions of variable curvature and variable height to accommodate to the variation of curvature and section height. A MATLAB numerical analysis program has been implemented.

Time Domain Computational Analysis for Shock Characteristics of Elastic Support Gearbox

2011 ◽  
Vol 86 ◽  
pp. 323-326
Author(s):  
Guang Hao Dai ◽  
Chang Wei Gao ◽  
Yong Heng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Time Domain ◽  
Computational Study ◽  
Element Model ◽  
Elastic Support ◽  
Shock Load ◽  
Load Spectrum ◽  
Element Analysis ◽  
Load Effect

Shock load spectrum of elastic support gearbox is confirmed by Federation Wehrmacht vessel construction rules BV0430/85 standard, and convert into equivalent double-triangular wave acceleration shock load. We take one elastic support gearbox which used in a vessel as computational study subject. With the help of ABAQUS software, we establish finite element model of elastic support gearbox and put double-triangular shock load into finite element model. Taking finite element analysis method do time domain response characteristics numerical simulation research of elastic support gearbox with limited bit and unlimited bit design, respectively, under shock load effect.

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