The RAM Steel Beam/Joist Module optimizes steel beams, Smartbeams and open web steel joists. Unsized lateral beams are also assigned an optimum preliminary size based on gravity loads from one-way decks only (and without consideration of end fixity or braces). Gravity beams and Smartbeams may be composite or non-composite but must be covered entirely with composite deck to be designed as such. All beams in this module are assumed to be simple supported and they are designed for Dead and Live Loads only. This section can only be completed if you have installed the RAM Steel program and have a license available.
To invoke the gravity beam module from RAM Manager:
When the Beam program is invoked for the first time after saving the model in the Modeler, the Framing Table Options dialog box opens.
At this stage the program will apply surface, line and point loads to members, transfer loads to supporting members and calculate Live Load Reduction factors (this is referred to as "Building the Framing Tables"). The option to design the members is presented to the user before building the framing tables. Since the design criteria have not been reviewed:
At first the graphical screen is empty. To see the typical floor in the model:
This sets the Typical floor to the current floor in much the same way as it is done in the modeler.
Steel beams may be designed per requirements of seven different codes including AISC 360-05 (ASD and LRFD), Allowable Stress Design (ASD), Load and Resistance Factor Design (LRFD), Canadian (CAN/CSA - S16.1 - 94), British (BS5950:1990 or 2000), Eurocode and AS 4100-98. Smartbeams may only be design according to the ASD and LRFD codes. Joists are not designed by the program but rather selected from the manufacturer's table of Total and Live Load capacities. These tables are in the RAM\Tables directory, they have the extension .JST and may be edited with any text editor. For more information about design codes see the Design Codes Section in the RAM Steel Beam on-line documentation. For more information about joist tables see the Tables section in the Manager manual.
To establish the design code for steel beams:
The design of beams is guided by the various criteria set under the Criteria menu. For each of the design modules it is critical that the user understand the criteria completely. In this tutorial you can use the default criteria of modify the settings to match the values shown hereafter. Refer to the Steel Beam Module documentation for a more detailed explanation of the various criteria.
Note: These criteria can also be set through the RAM Defaults Utility in RAM Manager so that future projects use the setting you choose.
Note: When using different design codes, the wording of the criteria dialog boxes may vary slightly. In some cases there are even code-specific options to choose. Below are the same options when using the BS 5950:2000 code.
When the Design Criteria are altered, a warning will pop up indicating the following:
Note that this tutorial has noncomposite steel beams (and joists) as well as composite, unshored beams. There are no shored beams because there is no shored deck defined in the model.
Beam members are now ready to be designed. The Process - Design All menu item may be selected to perform the design of all beam members or the Process - View/Update menu item may be selected to look at one particular member.
The program will design all beams, Smartbeams and joists. In order to track beam self weight reactions, the program designed the top level infill beams first, then moves to the girders and then repeats for the levels below.
A dialog box may appear indicating that there are design warnings in the model. If so click [Yes] to review the Design Warnings report. Click the "X" in the corner to close the report.
Design warnings always include the beam number. Beam numbers can be displayed in the Steel Beam module using the command View - Show Beam Numbers.
A beam can be also by found using the Find-Beam command.
Note: The View - Zoom command may be used to better see the selected beam sizes. The View - Scale Text command can be used to adjust the text size as necessary. All of these controls can also be accessed through toolbar buttons.
To investigate a selected member size:
Notice that the cursor now has a "target" shape. Also notice that at the bottom left corner of the screen there is a prompt for the expected action saying "Select a Beam to Edit or Update".
The View/Update Dialog box opens. This dialog box is used to investigate, modify and update the design of single members. You can change size, shape, yield stress, section type, composite flag or stud configuration and re-analyze the beam. For a complete explanation of how the program designs beams refer to the RAM Steel Beam documentation.
To view the loads on the beam:
A Loads Report will come up showing the line and point loads on the beam. When there is a change in the uniform load at a given location, the value is listed just to the left and right of that point.
To view the shear moment and deflection diagrams for the beam:
The following interactive dialog box opens:
Notice that force and deflection magnitudes on the right hand side reflect the cursor location on the graphic. The mouse automatically controls the cursor when on top of the diagrams. The diagrams for this beam may be printed by clicking [Print] button in this screen.
To inspect the complete design results for the beam:
A Design Report will come up showing various calculations for the beam. This includes information about the composite properties of the member, controlling moments used in the design (along with the applicable unbraced length) and deflections. If the report is more than one page long, click the forward triangle or press the Page Down key to see the next page. Take time to become familiar with this report. This report can also be called in the reports menu at Reports-Beam Design-Single.
To check the design of a different section:
Another dialog box will open showing the new optimized stud configuration based on the new beam size. In this case the required number of studs is less than in the original design. In other situations, the user selected size might produce a design warning.
Click [OK] to accept the new stud configuration.
At this point you can go on to review the loads, diagrams or design results for the new trial section.
To override the optimum selection with this new design
Note: When the Update Data Base command is performed, the new section size will be assigned to that beam permanently (the design is "frozen"). You will receive a design warning if that design should ever fail the strength or deflection checks that the program performs, but a new size will not be selected unless you clear the beam size. This can be done from within the Modeler using a Clear Size command or in the Beam Module by selecting Process - Clear Size - Single.
At this point you may wish to review other beams or joists in the model. The cantilevered beams on the 3rd and 4th levels and the Joists on the Roof level are of particular interest.
When finished, look into the lower-right corner of the screen. A model status light (a.k.a. traffic light) indicates the status of the model. At this time, the light should be yellow, indicating that there has been some change to the model that has affected reactions on other members. This is the result of changing a beam size in the View/Update dialog. The change in self-weight affects the reactions on other members.
To make sure all the designs are current:
Notice that the model status light is now green which means that all beams in this model are designed.
Another way to investigate a single beam is by using the RAM SBeam program. You can export any steel beam from your models to the SBeam program(if currently installed) and investigate resize and design them in a 3-d view not offered in the steel beam module. To do this ensure a current floor layout is displayed, then select Process-Export to SBeam and use the target cursor to select a beam. See the SBeam manual for further instructions on how to use the program.
All printable reports except for the shear, moment, and deflection diagrams are available under the Reports menu item. The Reports - Map Fence and Reports - Map Floor reports print the plan view of a floor type with options to show surface, line and point loads together with beam designs. The Framing Check and Connection Check reports check the intersection of beams and report possible fit-up problems. For a better explanation of the various reports available see the Beam Manual.
To see any of these reports on the screen first:
The Summary Design report lists all gravity beams by Floor and by Number with the controlling Moments, Section Size, Studs, etc. To see the Summary of beam designs for the tutorial model:
Note: If Smartbeams are included in a model, a third choice for Smartbeams appears in this dialog.
Feel free to review other design reports at this time. Of particular interest is the Material Takeoff report. The Connection design report only functions after a connection table is written. Refer to the RAM Manager documentation for instructions on creating connection check tables.
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