Steel Design in MasterPort

The portal frame design process in MasterPortPlus is basically the same as MasterPort, with additional management facilities made available.

MasterPort – Getting Started Tutorials include:-

The additional features available in MasterPortPlus include:

Design briefs are automatically created for all the members in the structure. The members are automatically grouped into design subsets to make the whole design process much simpler.
Design subsets are created for all the various parts of the structure. These subsets include the main portal (including lean-tos), secondary members (canopies, parapets and mezzanine floors), roof, wall, floor, and gable bracing, gable frames (South or North), and gable posts. These subsets are shown in the icons at the bottom of the frame graphics area. Each design subset can be selected in turn.
In each design subset there can be a single member group, or a number of member groups. For example, the main portal (M) could consist of several member groups, these being external columns, the internal columns, outside rafters, and internal rafters. The wall bracing (Bw) design sub set could have a separate member group representing the bracing for each wall.
The program automatically sets up design briefs for each member group within each design subset. For example, in the main portal design subset (M), all the external columns would be in a member group which has one set of design briefs applicable to all these columns – an axial with moment check and an associated Appendix G (or Annex BB) check.

When carrying out an automatic design, the worst loaded external portal column would be selected and designed, and the whole member group would then assume that same section size.

The “Full Frame” option allows you to toggle between the full 3D frame and the members of the particular design group selected. This can be useful for clarifying which members of the structure are in a particular design group.
The “Check Critical Cases” option speeds up the design of members by selecting only those load cases which form the design envelope, or are within 90% of the envelope. This may involve only a few critical cases.
The selection of the critical cases is only highlighted in the title of the design calculations on the left hand side of the screen. This option should be used to quickly design the frame, however, before signing off the design, it is advisable to switch this mode off and check the design of the structure for all load cases.
Generate 3D Frame. This option will allow you to switch between the full 3D frame and a plane frame, analysing the frame each time you switch between types.

Main Portal Design

Note that the portal frame being checked is the frame number which was set in Current Frame within the 3D Bays tab in the editing end of the program. This frame will be highlighted in the frame graphics area on the right of the screen.

You can go into the main portal design subset (M) and carry out an auto design of the main portal spans using either a plastic or an elastic analysis. After sizing the frames using the Auto Size All

option, the purlin and cladding rail positions can be optimised. After this torsional restraints can be automatically added using the Auto Restrain All option.

As a final check on the members of the frames you can use the Scan For Failures button. This will look at all the members of the current group and check each portion automatically.

On completion of the design of the current main portal frame, you should check all the other main portals as their section sizes will have assumed those of the current frame. Click on the portal frame you wish to check and run the Find Next Fail option to check the frame members. This should be carried out particularly where the frame spacing’s vary from the common spacing.

You also have the option to consider different partial fixities for the column bases – 0/10/20 and As is. The 0/10/20 option will apply pinned bases in all ultimate load cases, 10% fixity in the sway load case, and 20% fixity in all other service load cases. The As is option will apply the amount of fixity, if any, specified in the dynamic interface when setting up the structure for all loading cases.

Change

Design of All Other Members

By selecting each design subset in turn, from the icons at the bottom of the graphics area, you can look at each set of groups and automatically design the members in turn. The method of design for the remaining subsets uses the automatic design functions.

	Sort by Weight. This sets the section sizes into weight order when clicked down, otherwise sections are arranged by section depth.
	Auto Size All. Auto size all members within the frame. This function uses the automatically assigned member groups such as rafters, columns etc. and auto designs each group to use the same section.
	Auto Restrain All. Opens the auto restraints menu where a variety of member restraints can be applied to each member group.
	Elastic Analysis. Removes all plastic hinges and analyses the frame elastically.
	Plastic Analysis. For any members that fail the elastic analysis, the plastic analysis will insert a plastic hinge in that member. The resulting effect on surrounding members will then be analysed.
	Check for Failures. Having re-analysed the frame, select each design subset in turn and check for any design failures which may now occur due to re-analysis.
	Move to Next Failure. If failures are found, you can re-design these members and then, using this option, move on to the next failure (if they exist).