Bridge Girder Diagrams

Function

• The member forces and stresses of each element constituting the bridge girders are produced in the form of a graph. The stresses due to axial forces and bending moments may be combined and compared with the allowable stresses.

Call

From the ain menu, select [Results] tab > [Type : Bridge Specialization] > [Diagram] group > [Bridge Girder Diagram]

Input

Bridge Girder Diagrams dialog box

Load Cases/Combinations

Select the load cases/combinations for which the results output is desired. When a construction stage analysis is carried out for a bridge structure, the following loading conditions are auto-generated and the analysis results are saved separately.

Using the auto-generated loading cases, loading combinations may be formulated in "Combinations". The results for the auto-generated load cases as well as the additional load combinations can be checked for each construction stage including the Min/Max of each stage.

Dead Load : Analysis results for all the dead loads included in the construction stages including the Self Weight.

Erection Load : Analysis results due to all permanent loads applied to the construction stages excluding Dead Load.

For further details on Erection Load, refer to Analysis> Construction Stage Analysis Control.

Tendon Primary : Analysis results for prestressing forces in tendons.

Tendon Secondary : Analysis results for indeterminate condition between the prestressing forces in tendons and the bridge structure. (secondary stress)

C&S Primary : Analysis results for creep and shrinkage effects.

C&S Secondary : Analysis results for creep, shrinkage, and statically indeterminate conditions of the bridge structure (secondary stresses).

Summation : Analysis results summing up all the conditions above (Summation = Dead Load + Erection Load + Tendon Primary + Tendon Secondary + Creep Secondary + Shrinkage Secondary)

In the Final Stage, analysis results for automatically generated load conditions cannot be verified. However, it is possible to verify the analysis results for additional input load combinations.

Step List

When a construction stage analysis or a geometric nonlinear analysis is performed, select the steps for which the analysis results are desired. Several steps may be selected, and the results may be produced in one graph.

Load Case/Combination

Select the load cases/combinations.

Diagram Type

Select a diagram type for the graphs of the results to be produced.

Stress : Display normal stress diagram.

Force : Display force/moment diagram.

Batch : Display a diagram by selecting the predefined diagram group. For example, top stress and bottom stress diagram can be displayed at the same time in one graph.

X-Axis Type

Select the representation type for the x-axis.

Distance : Distance from the starting point.

Node : Node numbers (not to scale)

Bridge Girder Elem. Group

Select the element group that contains the girders for which the results are desired.

If Bridge Wizard is used for modeling, the main girders will be assigned the element group name, "Bridge Girder".

Components to combine

Select the desired stress component among the following:
If multiple stress components are selected, the maximum vertical stress resulting from the combination of stresses for each component will be displayed.

 Sax : Axial stress in the element's local x-direction.

+Sby : Bending stress at the element's local (+)y-end resulting from the moment (Mz) about the element's local z-axis.

-Sby : Bending stress at the element's local (-)y-end resulting from the moment (Mz) about the element's local z-axis.

+Sbz : Bending stress at the element's local (+)z-end resulting from the moment (My) about the element's local y-axis.

-Sbz : Bending stress at the element's local (-)z-end resulting from the moment (My) about the element's local y-axis.

Combined(Axial+Moment) : Combined stress representing the absolute largest among combined stresses at 1, 2, 3 and 4

Maximum : Combined stress representing the absolute largest among combined stresses at 1, 2, 3 and 4

1(-y,+z) : combined stress at 1

2(+y,+z) : combined stress at 2

3(+y,-z) : combined stress at 3

4(-y,-z) : combined stress at 4

Fx : Axial force in the element's local x-direction

Fy : Shear force in the element's local y-direction

Fz : 요Shear force in the element's local z-direction

Mx : Torsional Moment about the element's local x-direction

My : Bending Moment about the element's local y-direction

Mz : Bending Moment about the element's local z-direction

Allowable Stress Line

When 'Stress' is selected in Diagram Type, specify whether to display the allowable stress line.

Draw Allowable Stress Line : Check on to draw the allowable stress line.

Comp. : Allowable compressive stress.

Tens. : Allowable tensile stress.

Generation Option

Current Stage-Step : Produce the graph for the current construction stage or step.

Stages (Last Step) : Produce the graphs for multiple construction stages/steps simultaneously.

... : Click to prompt the Stage Output Detail dialog box and select the desired construction stages/steps for the production of diagrams.

Select stages to output

Check on the desired construction stages/steps for Diagram production. The diagrams are produced using the Last Steps of each construction stage.

Auto-save graph

The diagrams may be saved as graphic files. Specify the file path, name and type.

When selecting in batch mode, it is possible to simultaneously view multiple graphs of structural forces/stresses at desired cross-section locations.

Context Menu

When right-clicking on the Bridge Girder Stress Diagram screen, the following Context Menu is invoked.