MDX Software - Frequently Asked Questions

1.	Why is the warning "Must run complete analysis to obtain results based on latest stiffnesses" given?
2.	Why is the warning given about stiffeners being near splices?
3.	How is the lateral moment from curvature in a flange, between braces, determined?
4.	Are horizontal cross frames used in the analysis if the condition WIND BRACING ALL BAYS or WIND BRACING EVERY OTHER BAY is given?
5.	Why did I get a significant overstress when designing with self weight as the noncomposite dead load?
6.	How are regions of composite section properties determined for stiffness analysis?
7.	What sign convention is being used? I cannot seem to correlate signs on loading effects with the x-y coordinates used in the geometry table of the system analysis output.
8.	How is the stiffness of a cross frame determined for use in system analysis?
9.	How are internal and external bracing given in box girders in Girder System Projects?
10.	What is the meaning of the message at the end of the warning file: "above warnings may not be comprehensive" ?
11.	Are connection plates assumed to act as web stiffeners?
12.	What is the procedure for determining governing forces in cross frame members?
13.	Why are the deflections across the system not the same when I use the condition AVERAGE LIVE DEFLECTIONS?
14.	I noticed some slight variance with span values of girders other than girder 1 from those generated by the parallel/concentric model in system projects and those generated by our in-house geometry generator. What might cause this?
15.	Why can't I match any of the values listed in the governing shear and moment tables in the girder output with the three tables shown separately for the AASHTO truck, AASHTO lane, and defined truck?
16.	How do the performance ratios and live load multiplier in the Live Load Capacity table relate to the inventory rating shown in the rating table?
17.	What is the difference between moment strength as shown in the strength tables, and moment capacity as tabulated in the rating table?
18.	Dead loading effects easily are checked with an independent analysis program, but how can I check system analysis live loading effects?
19.	How can a diaphragm brace be overstressed when it is connected to the connection plates with only a few bolts on the web?
20.	Why do I get significantly different results using the same wheel distribution on girders of a system that I use on a single girder of that system modeled as a line girder project?
21.	How can I get the program to successfully generate a girder design? I keep getting abort messages that begin such as: "Computational difficulty during search..."
22.	I have multispan symmetric geometry and loading, yet the design which is generated has unsymmetric flanges. Shouldn't they be symmetric?
23.	What is an appropriate choice for bracing connection offset (GCONNDST) for box girders?
24.	How are live loading effects determined in a system project if lanes are defined?
25.	I cannot check a particular value with my own calculations. How do I resolve the difference?
26.	How can I apply both permit and standard truck loading at the same time?
27.	How is the "Theoretical Flange Splice Location" in the Dimensions table determined?
28.	What is the meaning of the table heading 'Lateral Bending Moment (x girder ht)' in the system analysis output?