Load distribution in continuous composite bridges

1983 ◽  
Vol 10 (3) ◽  
pp. 384-395 ◽  
Author(s):  
John B. Kennedy ◽  
N. F. Grace
Keyword(s):  
Load Distribution ◽  
Transverse Load ◽  
Design Parameters ◽  
Skew Angle ◽  
Composite Action ◽  
Transverse Cracking ◽  
Composite Bridges ◽  
Current Design ◽  
Bridge Models ◽  
Concrete Deck

The influence of transverse diaphragms on the load distribution in composite bridges has been minimized in current design codes. Tests have shown that when diaphragms having an I-section are rigidly connected to the longitudinal girders, a rigid gridwork is formed; this gridwork in composite action with the concrete deck distributes the wheel loads on the bridge in an orthotropic manner. In this paper, the influences of the number of diaphragms, aspect ratio, skew, and cracking of the concrete deck on the transverse load distribution in continuous composite bridges are examined. The theoretical results are verified and substantiated by tests on two 1/8-scale bridge models. The results indicate that such diaphragms, rigidly connected to longitudinal girders, significantly enhance the transverse load distribution, and thus a reduction in the design load for the girders results; the degree of this enhancement increases with increase in the width as well as the skew angle of the bridge. Furthermore, transverse cracking of the concrete deck at the intermediate support(s) does not appear to influence significantly the transverse distribution of the design parameters.

Load Distribution for Moment and Shear on Skewed Bridge Structures

2011 ◽  
Vol 255-260 ◽  
pp. 1244-1247
Author(s):  
Yi Zhou Zhuang ◽  
Tao Ji ◽  
Bao Chun Chen
Keyword(s):  
Load Distribution ◽  
Distribution Factor ◽  
Skew Angle ◽  
Shear Distribution ◽  
Moment Distribution ◽  
Bridge Structures ◽  
Skewed Bridge ◽  
Aashto Lrfd ◽  
Skew Angles ◽  
Bridge Models

Based on FEA for three bridge models with varying skew angles, the effect of skew angle on the design moment and shear of skewed bridge structures was studied and also compared to AASHTO specifications. The results show that, generally, ASSHTO-LFD covers FEM in moment distribution factor, but a little less in shear distribution factor, and that, however, AASHTO-LRFD reduces moment distribution factor below AASHTO-LFD and near to FEM, but increases shear distribution factor a lot beyond AASHTO-LFD and FEM.

Laboratory Testing of Stress-Laminated Wood Decks on Steel Beams

1997 ◽  
Vol 1575 (1) ◽  
pp. 47-52
Author(s):  
Barry Dickson ◽  
Hota GangaRao ◽  
Vijith Vijayachandran
Keyword(s):  
Load Distribution ◽  
Laboratory Testing ◽  
Static Load ◽  
Theoretical Calculations ◽  
Construction Cost ◽  
Transverse Load ◽  
Steel Beams ◽  
Composite Action ◽  
Static Testing ◽  
Load Tests

Four different stress-laminated wood decks were laboratory-tested to measure composite action between deck and steel beams, transverse load distribution, performance of connectors, and deck construction cost. The models were subjected to cyclic loading varying from 9 to 89 kN. Static load tests were conducted after every 100,000 cycles. During static testing, strains and deflections in the beams were measured at 22, 44, 67, and 89 kN. The loss of tension in the connectors was also monitored after every 100,000 cycles. The readings were used to compare the composite action, load distribution, and tension loss in connectors. Load distribution values were verified with theoretical calculations.

Shear distribution in simply supported skew composite bridges

1995 ◽  
Vol 22 (6) ◽  
pp. 1143-1154 ◽  
Author(s):  
Tarek Ebeido ◽  
John B. Kennedy
Keyword(s):  
Parametric Study ◽  
Load Distribution ◽  
Experimental Program ◽  
Distribution Factor ◽  
Simply Supported ◽  
Shear Distribution ◽  
Truck Loading ◽  
Composite Bridges ◽  
Bridge Models ◽  
Composite Steel

Composite steel–concrete bridges remain one of the most common types built. Proper design of new bridges and evaluation of existing bridges requires accurate prediction of their structural response to truck loads. The American Association of State Highway and Transportation Officials has traditionally applied a load distribution factor for both moment and shear. The Ontario Highway Bridge Design Code (OHBDC) considers several parameters in establishing load distribution factors for moment. However, the method is limited to bridges with skew parameters less than a certain value specified in the code. The presence of skew reduces the longitudinal moments in the girders. However, it also causes high concentration of shear in the girder closest to the obtuse corner and reduces shear concentration in the girder closest to the acute corner as well as in the interior girders. Therefore, shear should be considered in the design of such bridges. In this paper, the influence of skew on the shear distribution factor is investigated. The influences of other factors such as girder spacing, bridge aspect ratio, number of lanes, number of girders, end diaphragms, and intermediate cross-beams are presented. An experimental program was conducted on six simply supported skew composite steel–concrete bridge models. Results from a finite element analysis showed excellent agreement with the experimental results. An extensive parametric study was conducted on prototype composite bridges subjected to OHBDC truck loading. The parametric study included more than 400 cases. The data generated were used to develop empirical formulas for shear distribution factors for OHBDC truck loading and also for dead load. An illustrative example is presented. Key words: bridges, codes of practice, composite, distribution, reaction, reinforced concrete, shear, skew, structural engineering, tests.

Front steering design guidelines formulation for e-scooters considering the influence of sitting and standing riders on self-stability and safety performance

2021 ◽  
pp. 095440702199217
Author(s):  
Milan Paudel ◽  
Fook Fah Yap
Keyword(s):  
Preventive Measures ◽  
Recent Trend ◽  
Dynamic Performance ◽  
Design Guidelines ◽  
Safety Performance ◽  
Design Parameters ◽  
Single Track ◽  
Standing Posture ◽  
Last Mile ◽  
Current Design

E-scooters are a recent trend and are viewed as a sustainable solution to ease the first and last mile problem in modern transportation. However, an alarming rate of accidents, injuries, and fatalities have caused a significant setback for e-scooters. Many preventive measures and legislation have been put on the e-scooters, but the number of accidents and injuries has not reduced considerably. In this paper, the current design approach of e-scooters has been analyzed, and the most common range of design parameters have been identified. Thereafter, validated mathematical models have been used to quantify the performance of e-scooters and relate them with the safety aspects. Both standing and seated riders on e-scooters have been considered, and their influence on the dynamic performance has been analyzed and compared with the standard 26-in wheel reference safety bicycle. With more than 80% of the accidents and injuries occurring from falling or colliding with obstacles, this paper tries to correlate the dynamics of uncontrolled single-track vehicles with the safety performance of e-scooters. The self-stability, handling, and braking effect have been considered as major performance matrices. The analysis has shown that the current e-scooter designs are not as stable as the reference safety bicycle. Moreover, these e-scooters have been found unstable within the most common range of legislated riding velocity. The results corroborate with the general perception that the current designs of e-scooters are less stable, easy to lose control, twitchy, or wobbly to ride. Furthermore, the standing posture of the rider on the e-scooter has been found dangerous while braking to avoid any disturbances such as potholes or obstacles. Finally, the front steering design guidelines have been proposed to help modify the current design of e-scooters to improve the dynamic performance, hence the safety of the e-scooter riders and the surroundings.

Analytical Model of the Efficiency of Spur Gears: Study of the Influence of the Design Parameters

2011 ◽  
Author(s):  
Miguel Pleguezuelos ◽  
Jose´ I. Pedrero ◽  
Miryam B. Sa´nchez
Keyword(s):  
Load Distribution ◽  
Gear Ratio ◽  
Design Parameters ◽  
Spur Gears ◽  
Transmitted Power ◽  
Power Losses ◽  
Contact Ratio ◽  
Complete Study ◽  
Uniform Model ◽  
Analytical Expressions

An analytic model to compute the efficiency of spur gears has been developed. It is based on the application of a non-uniform model of load distribution obtained from the minimum elastic potential criterion and a simplified non-uniform model of the friction coefficient along the path of contact. Both conventional and high transverse contact ratio spur gears have been considered. Analytical expressions for the power losses due to friction, for the transmitted power and for the efficiency are presented. From this model, a complete study of the influence of some design parameters (as the number of teeth, the gear ratio, the pressure angle, the addendum modification coefficient, etc.) on the efficiency is presented.

scholarly journals Calculation features of wall panels with monolithic cement bond of layers in the stages of installation, transportation and maintenance

Vestnik MGSU ◽  
2019 ◽  
pp. 367-375 ◽  
Author(s):  
Elena A. Korol’ ◽  
Marina N. Berlinova
Keyword(s):  
Middle Layer ◽  
Structural Features ◽  
Design Parameters ◽  
Competitive Advantages ◽  
Design Standards ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Current Design ◽  
Infinite Variety ◽  
Construction Practice

Introduction. When building residential, public and administrative buildings of various spatial structural designs (monolithic, precast-monolithic, precast, etc.), it is common practice to design self-sustaining (non-structural) outer walls within a storey. Developing and using new design and fabrication solutions of multilayer industrial-made wall panels in modern construction practice makes actual the issue of improving methods of their calculation in different stages of maintenance and under various sorts and combinations of loads and effects. However, there is an infinite variety of possible loading levels in practice and, therefore, the same variety of design approaches would be required. This is obviously unacceptable for engineering calculations, hence it is necessary to provide a monolithic matrix bond of layers, both technologically and structurally, which can provide a generalized approach to the calculation of multilayer enclosing structures in accordance with current design standards. Materials and methods. The article describes structural features of a multilayer wall panel made of structural concrete with the middle layer of concrete with low thermal conductivity and monolithic bond of layers. These features have an influence on creation of a design model and a calculation procedure in the stages of transportation, installation and maintenance. Results. The article has examined the structures described above in the sense of design parameters that provide their competitive advantages in strength and maintenance as compared with conventional mass-built enclosures. Conclusions. The studies demonstrate that when combining loads of force and non-force character, stresses in the considered structure do not exceed allowable values in all the stages what proves the prospects of using the multilayer panels with monolithic bond of layers for erection of various-purpose frame-panel buildings.

scholarly journals A Study on Calculation Theory and Method of Transverse Distribution Coefficient of the Corrugated Steel Web Box Girder Based on the "Modified Rigid Jointed Beam Method"

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Wang Jie
Keyword(s):  
Distribution Coefficient ◽  
Load Distribution ◽  
Internal Force ◽  
Transverse Load ◽  
Box Girder ◽  
Steel Box Girder ◽  
Calculation Process ◽  
Beam Method ◽  
Corrugated Steel Web ◽  
Girder Bridge

Abstract: The PC box girder Bridge with corrugated steel web, as a new kind of bridge structure, has different mechanical properties from that of the ordinary concrete box girder bridge. Due to the late development of the corrugated steel web pre-stressed box girder structure, the domestic experts have made little research on the transverse load distribution of PC box Girder Bridge with corrugated steel webs. Whether the method of calculating the transverse distribution coefficient in the classical box girder theory can be applied to the corrugated steel web composite box girder and how to further improve the calculation theory and method of the transverse load distribution of the steel box girder bridge need urther study. method of the transverse load distribution of the steel box girder bridge need further study.Based on the "traditional rigid jointed process and the programming ideas of the transverse distribution coefficient of corrugated steel web composite box girder of the "modified rigid jointed beam method".beam method" and the existing research, this paper proposes the "modified rigid-jointed beam method" in combination with the specific internal force distribution of corrugated steel web composite box girder. The computational scheme and formula of mechanics, the calculation process and the programming ideas of the transverse distribution coefficient of corrugated steel web composite box girder of the "modified rigid jointed beam method".

Performance of the Air-Cushion–Surface-Contacting Hybrid Vehicle for Overland Operation

1972 ◽  
Vol 186 (1) ◽  
pp. 613-623
Author(s):  
J-Y. Wong
Keyword(s):  
Power Consumption ◽  
Load Distribution ◽  
Road Transport ◽  
Hybrid Vehicle ◽  
Considerable Effect ◽  
Control Device ◽  
Design Parameters ◽  
Optimum Load ◽  
Air Cushion ◽  
Cross Country

The air-cushion concept has been considered for application to off-road transport ever since the early days of its development. Recently, the rapid increase in resource exploration and exploitation in remote areas has stimulated new interest in applying air-cushion technology to overland transportation. It appears to offer solutions to a wide variety of cross-country transportation problems. Although existing vehicles fully supported by an air cushion can function overland, experience to date indicates that considerable improvements in controllability and manoeuvrability are required for continuous overland operation. One practical solution is to provide some degree of surface contact. The feasibility of an air-cushion–surface-contacting hydrid vehicle has been demonstrated by the Benin Terra-plane BC7, Vickers-Armstrongs Hovertruck, etc. However, the operating performance, capabilities and limitations of this type of vehicle have not been investigated in a systematic way. This paper attempts to provide a theoretical basis for evaluating and optimizing the performance and design of the hybrid vehicle. The basic power requirements of this type of vehicle are first analysed and compared with those of the fully-air-cushion-supported vehicle. The approaches to minimizing the power consumption and to improving the economics of operation are then investigated. It is found that among other design parameters, the load distribution between the air-cushion and the ground-contacting gear of the hybrid vehicle has a considerable effect on its power requirements. For a given vehicle in a particular type of terrain, there is an optimum load distribution which minimizes the power consumption. Finally, an analytical approach to evaluating and predicting the controllability and mobility of this kind of vehicle is discussed. It is found that using the wheel as a yaw-control device for the hybrid vehicle is quite effective. It is also shown that wheeled propulsion has limitations in cross-country operation. In order to provide the hybrid vehicle with adequate off-road mobility, an auxiliary air propulsive system appears to be necessary.

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