May 26 th, 2017 MWF Truss User Guide
1 1. Introduction... 3 1.1 Things to Know Before Starting... 3 1.1.1 Revit Model... 3 1.1.2 Roof... 3 1.1.3 Adding Families... 4 2. Envelopes... 5 2.1 General Envelope Creation... 5 2.1.1 Creating a Truss Envelope Automatically... 6 2.1.2 Creating/Editing a Truss Envelope Manually... 9 2.2 Truss Profiles Envelopes...10 2.2.1 Common Trusses...10 2.2.2 Valley Trusses...11 2.2.3 Hip Trusses...13 2.2.4 Ridge And Parallel Jack Trusses...14 2.2.5 Ridge Truss...16 2.2.6 Perpendicular Jack Trusses...17 1.1.1 Hip End...19 1.1.2 Half Trusses...20 2. Framing an Envelope...22 2.1 Presets...22 2.2 Creating Truss Members...25 2.3 The Truss Designer...26 2.3.1 Assigning Properties of Element Lines...26 2.3.2 Generating Web Lines...27 3. Truss Properties...28 3.1 Elements Visualization...28 3.2 Flip the Direction of a Web Member...29 3.3 Deleting a Member of the Truss...29 3.4 Adding a Member in the Truss...30 3.5 Adding a new Node...30 3.5.1 Adding On Member Nodes...31
2 3.5.2 Adding Off Member Nodes...32 4. Tools Menu...33 4.1 Add/Remove Supports...33 4.2 Update Supports...34 4.3 Split Cap...35 4.4 Scissor...35 5. Edit Single...36 6. Input / Output...36 6.1.1 BOM Report...36 7. Truss Engineering...37 7.1 Engineering Presets...38 7.1.1 General...39 7.1.2 Deflection...40 7.1.3 Wind...40 7.1.4 Snow...40 7.1.5 Combinations...41 7.2 Truss Analysis and Design...41 7.2.1 Node Options...43 7.2.2 Display Loads...44 7.2.3 Diagrams...45 7.3 Reports...45 7.4 Manage...48 8. Floor Trusses...48 8.1 Floor Engineering...50 8.2 Truss Profile Approach... Error! Bookmark not defined.
1. Introduction 3 This manual highlights the features that can be used to create a truss project, based on standard commercial definitions. Each topic demonstrates tools that you can use to complete tasks that are common to an overall workflow. You will learn some of the practices that can help you efficiently design and develop a truss framing project, using a 3D Revit model as a start point. 1.1 Things to Know Before Starting When starting a project and using MWF Truss there are a few basic things one should know before getting started with the software. 1.1.1 Revit Model In general terms, you will need to have a complete and final Revit project consisting of, at the least, a roof and its supports: walls and/or any other structural element that will support or represent the support of the truss (beams or model lines). 1.1.2 Roof Make sure layers, slope and overhangs of the roof are accurate; MWF Truss will use the geometry and position of these elements to generate the truss envelope. By default, the truss envelope (lines created on the outermost boundary of the truss's top chord, bottom chord and heels) is created aligned to the outer face of the roof. An offset distance can be added to adjust the truss to the project needs.
4 Trusses can also be created using multiple roof elements. When creating a truss that is spanning multiple roof planes, MWF Truss will consider the outmost face of the roofs to create its envelope. 1.1.3 Adding Families If you want to use certain families to create trusses, the description parameter must include Profile and the Truss Type separated by a space. For example, a Cee type section will have the description Profile BIMSF-C.
5 To alter an entire catalogue, open the family.rfa file in Revit. Select the Family Types command under Properties: Under Identity Data, alter the description parameter to match the family. You can then load the family into the project and have it available in Member Sizes. 2. Envelopes The first step towards the creation of the truss project is to create the truss envelopes. The envelope is a group of model lines create at the boundaries of the truss elements (when in elevation) and it is centred in the middle of the truss (when in plan view). It will represent the truss until the final creation of its members. 2.1 General Envelope Creation We will consider the General Envelope as being the result of using a section of the roof and its multiple planes to generate the truss envelope, or any other non-standard truss outline.
6 There are two methods to creating truss envelopes: automatically and manually. The automatic route is fastest and it will create the envelopes solely based on the roof s geometry, distributed along a specific length of the roof, usually limited by its supports. The manual way of creating a truss envelope is a freehand method of creating any desired shape, not necessarily bound to a specific roof s geometry. This can be used for the creation of more complex shapes, or in any other scenario independent of a roof element. The next few topics in this guide will explain the possible ways to achieve these. 2.1.1 Creating a Truss Envelope Automatically Select the roof element and click the Create command in MWF Truss. You will then be prompted to pick the roof supports. Click the 'Supports' button in the Create Envelopes dialog box and select two parallel walls that will support that area of the roof. Please note that beams and representative model lines can also be used as supports. Once you are done selecting the walls, click the 'Finish' button on the top of Revit's drawing area.
7 The Support Alignment dialog box will pop up. There you can view the default alignment options based on the support element. The Layer Align option will create the envelope at the structural layer in the drop down box. The Wall Align option will be used for the alignment of the truss's heels. Far would represent furthest from centre of truss. If you select a beam as a support, you can view the default alignment in the Beam Align area. With the Cantilever Offset option you can add an offset value for the heel positioning from the layer alignment that was chosen. Click Ok to continue with the envelope creation. The Create Envelopes dialog box will pop up once again. This time you can add options for the truss Spacing, placement of Offset From Outer Face for the chosen roof layer and to Add Additional Truss At End of roof.
If you need to space the trusses along a specific path, you can add an offset value to a picked location. You will see a green reference line that you can use to select the offset point by clicking Pick in the Offsets area, or you can use any other model line in the project to use as reference. 8 Note that the truss distribution is limited by the length of its shortest support. Click Ok in the Create Envelopes dialog box to add the truss envelopes and repeat the process by choosing new supports to complete your roof project. Model lines representing the truss envelopes will be created and grouped as Model Groups. They will be distributed along the roof based on the spacing previously chosen.
2.1.2 Creating/Editing a Truss Envelope Manually 9 You can simply create a single truss envelope manually by using Revit commands. First, create the profile of the envelope using Revit Model Lines, in a section or elevation view of your Revit project. Then, select all the newly created lines and use Revit's Create Group command to group the lines into a model group. MWF Truss will be able to use any model group to create a truss. Keep in mind that the truss will be created where the model group is, which may not be the desired location, if this is the case it is advised that you move it and copy the model groups to create new envelopes. You can also edit the model groups created (automatically or manually created envelopes) to adjust the lines to the needs of your project.
2.2 Truss Profiles Envelopes 10 Depending on the shape of the roof and the truss project requirements, you might need to create extra standard Truss Profiless in some parts of the roof, sometimes not achievable with the general automatic creation that was previously explained in this guide. For that, you can use the available standard Truss Profiles commands in the MWF Truss menu. These tools will also generate envelopes that will later be used for the truss creation. 2.2.1 Common Trusses The Common Trusses tool will generate trusses that will be distributed along the whole length of the truss ridge, independent of the length of the roof supports (walls and/or beams). In the example below you can see that even when one of the support walls is shorter than the ridge's length, truss envelopes are still created. To create a common truss envelope, select the roof and click the Common command in MWF Truss. A dialog box will pop up so you can select the Main Ridgeline and the parallel Supports of the roof. Adjust the options for offsets and spacing as explained in the previous topics of this guide. Truss Detail Options will be automatically filled in base on the profile of the roof and supports selected.
11 2.2.2 Valley Trusses When you have a "T" shape roof, you can generate trusses that will gradually change their size using the roof's valley lines as supports. For that, you can use the Valley Trusses tool. These trusses will be distributed along the ridge line of the roof. Before using this tool, you will need to have at least one common truss created in that "T" part of the roof. This truss will be used to limit the distribution of the valley trusses.
12 To start, click the command Valley in MWF Truss. A dialog box will pop up. Select the Main Ridgeline, Valley Lines, Last Truss and Supports as shown in the image below. Set the values for offsets and spacing as needed. Using Stub Truss will recess the bottom chord at a given value and enable an overhang. Once you click Ok, the Valley Trusses envelopes will be generated.
2.2.3 Hip Trusses 13 When you have a hipped roof, you can generate trusses that will gradually change their height using the roof's hip lines as references. For that, you can use the Hip Trusses tool. To start, click the command Hip in MWF Truss. A dialog box will pop up. Select the Supports and Hip Lines as shown in the image below. You then have the option to create multiple trusses or a single hip truss. Set the values for offsets and spacing as needed.
Once you click Ok, the Hip Trusses envelopes will be generated. 14 2.2.4 Ridge And Parallel Jack Trusses When you have a hipped roof, you can generate Ridge Truss and Parallel Jack Truss envelopes in one shot. For that, you can use the Ridge and Parallel Jack Trusses tool. These truss envelopes will be distributed under (ridge truss) and along the hip line of the roof (parallel jack trusses). Before using this tool, you will need to have at least one common truss created at the ridge/hip intersection or in the portion of the roof after the ridge. This truss will be used as support for the ridge truss and to limit the distribution of the jack trusses. To start, click the command Ridge and Parallel Jack in the Truss Profiles menu. A dialog box will pop up. Select the Support, the roof Face where the jack trusses will be placed and the Last Truss as shown in the image below. Set the values for offsets and spacing as needed.
15 Once you click Ok, the Ridge Truss under the hip and Jack Truss envelopes will be generated. Tip: Use this command to complete parts of the roof that require a truss under the hip line and additional half trusses on one side of the roof connected to the truss under the hip line (i.e. 'L' shaped roofs). If you need to create a complete truss system in a symmetrical hipped roof, you can use the tool Hip End that will be described later here in this guide.
16 2.2.5 Ridge Truss In a hipped roof, you can generate a single Ridge Truss envelope under the hip line of the roof. For that, use the Ridge Trusses tool. Before using this tool, you will need to have at least one common truss created at the ridge/hip intersection or in the portion of the roof after the ridge. This truss will be used as the support and limit of the ridge truss. To start, click the command Ridge in the Truss Profiless menu. A dialog box will pop up. Select the Supports and Hip Line as shown in the image below. Set the values for offsets and spacing as needed.
17 Once you click Ok, the Ridge Truss envelope will be generated. 2.2.6 Perpendicular Jack Trusses Once you have created the Ridge Trusses and Parallel Jack Trusses as described in the previous topics of this guide on both sides of a hipped roof, you can complete the rest of the roof by creating Perpendicular Jack Truss envelopes. For that, use the Perpendicular Jack Trusses tool. These trusses will be distributed along the hip lines of the roof and in the area between both hip lines, perpendicularly to the support truss. Before using this tool, you will need to have at least one common truss created at the ridge/hip intersection or in the portion of the roof after the ridge and the ridge trusses created in the previous topic. The last 'common' truss and the ridge trusses will be used as support for the perpendicular jack trusses.
18 To start, click the command Perpendicular Jack under the Truss Profiles menu. A dialog box will pop up. Select the Support (wall/beam), the Ridge Trusses, Hip Lines and Last Truss as shown in the image below. Set the values for offsets and spacing as needed.
19 Once you click Ok, the envelopes for the Perpendicular Jack Trusses will be generated. 1.1.1 Hip End When you have a hipped roof that has parallel supports on its sides, you can generate a complete group of truss envelopes in one shot (Ridge, Parallel and Perpendicular Jack trusses). For that, you can use the Hip End tool. These truss envelopes will be distributed under (ridge truss) and along the hip line of the roof (parallel and perpendicular jack trusses). Before using this tool, you will need to have at least one common truss created at the ridge/hip intersection or in the portion of the roof after the ridge. This truss will be used as support for the ridge truss and to limit the distribution of the jack trusses. To start, click the command Hip End under the Truss Profiles menu.
20 A dialog box will pop up. Select Hip Lines, Side Supports, End Support, and Last Truss as shown in the image below. Set the values for offsets and spacing as needed Once you click Ok, the Ridge Trusses envelopes under the hip lines and Jack Trusses envelopes will be generated. The Hip End tool will align trusses according to the selected spacing. It will also place a truss in the intersection of the ridge truss with the last common truss. 1.1.2 Half Trusses You can quickly place Half Truss envelopes in your project by using the Half Truss Tool. To use this tool, you only need a roof and its support. To start, click the command Half Truss under the Truss Profiles menu.
21 A dialog box will pop up. You are given the option to place Half Trusses by Roof Edge or by Girder Truss. To Place by Roof Edge, select the Supports and Ridge Line as shown in the image below. Set the values for offsets and spacing as needed. To place by Girder Truss, select the girder as the Last Truss and the roof Face as shown below. Half trusses will be placed along the girder at the chosen spacing and follow the profile of the roof Face. Once you click Ok, the envelopes for the Half Trusses will be generated.
2. Framing an Envelope 22 Once the truss envelope is created, you can create the truss by clicking the Create command. MWF Truss will use the envelope as a boundary for the truss elements. MWF Truss uses a Truss Designer engine to create and place all members according to the user's needs. In the truss creation process, you will have options to select the truss types, member types, designer settings, webbing settings and many other features. We will review what is involved in this process in the next few topics of this guide. 2.1 Presets Use the Presets command to set up initial information that will be used to design the truss. The Presets will keep the values saved as default in the project basis. The command Save As can be used to save the current settings as a preset in the list of presets. These settings can also be exported to another project or user by using the command Save File (Export) and loading the created file in the new project using the command Load File (Import).
23 In the General area you can set the Display Units of the truss designer, the Truss Category, and Truss type. You can set information about the Truss Name and Project Name you want to use in your project. The Engineering Only option will be discussed later in this tutorial. When you click the Webbing option you can find settings for the diagonal and vertical members of the truss. Select the member sizes to use in the truss by clicking the option Member sizes. You can pick different member sizes for top chord, bottom chord, webbing members and heels. In the Physical Member
24 area you can add extra tolerances for the Top and Bottom Tracks insertion and also choose a configuration for the end of the elements. Chord Pitch Break - Open: Chord Pitch Break - Lapped: Chord End Cut - In: Chord End Cut - Out: Some extra settings can be found in the Designer Preferences area. These are configurations for the elements that we will see once the truss designer is opened. In the Engineering settings you can add information that will be used by the Truss Analysis Engine to verify if a truss can meet the necessary limits to pass or if it fails its structural needs. More about the Engineering module will be discussed later in this tutorial.
25 The Reports field is also related to the Truss engineering analysis. Fill the setting up with information that you need to have printed in the generated reports. 2.2 Creating Truss Members To create the truss members after the creation of the envelopes, select the envelopes and click the command Create. Make the necessary modifications in the Settings area, these are basically the same settings as in the Preset command previously shown in this tutorial. Once you click Ok on the settings dialog box, the Truss Designer will open.
2.3 The Truss Designer 26 The Truss Designer is an advanced tool that allows the free creation of a truss with any possible shape and various configurations. If you started this process by using the Create command to create a truss from an envelope, you will see the basic elements of the truss - Top Chord, Bottom Chord and Heels - in the truss designer area. Using the truss designer's commands, you will need to adjust the properties of the existing lines and create the webbing elements. 2.3.1 Assigning Properties of Element Lines Every line in the Truss Designer represents one type of truss element. It is important to match the line properties with the real type of element so the truss can be properly created. These are the different element types in the Truss Designer:
27 - Top Track - Bottom Track - Heel - Diagonal Web - Vertical Web - Oddball When you select any of the existing lines and 'doubleclick' or press 'enter' in your keyboard, the Line Options dialog box will open. Select the option that represents the use of the selected element line. You can also change the size of the element. 2.3.2 Generating Web Lines To generate the truss webbing, click the tool Generate Web in the Truss Designer. Nodes will be created in the top and bottom chords and spaced based on the existent settings of the Truss Designer's Web configuration tab. They will be used to represent the intersection of vertical and diagonal web lines with the top and bottom chords. The lines representing the web elements will be created, connecting the nodes.
28 Click Ok in the Truss Designer dialog box to have the truss created in your project. The model group will be deleted and a new 'Assemblies' element will take its place. 3. Truss Properties To change any properties of the truss using the Truss Designer, simply select the truss in your drawing and click the command Properties in MWF Truss. Many different possibilities of changes in the properties of the truss will be discussed in this topic. 3.1 Elements Visualization The model lines created in the Truss Designer represent the outer boundary of the heels, top, bottom chords, and the centre line of the webbing. In the 'View' tab you can change the visualization settings so you can see the Physical Model representation. Choose Analysis View to see the analytical lines of the truss' elements. You can see both physical and analytical representations by clicking the option Physical and Analysis.
3.2 Flip the Direction of a Web Member 29 You can select any of the diagonal web lines and click the spacebar in your keyboard to have the line flipped. Once you click Ok in the Truss designer, the truss will be updated. 3.3 Deleting a Member of the Truss A member of the truss can be deleted when working within the truss designer. Open the properties of the truss by clicking Properties in the MWF Truss when you have the truss selected in your project. In the Truss Designer, simply select the line that represents the element you want to delete and hit the delete button in your keyboard. The element will be deleted and the truss will be updated once you click Ok in the Truss Designer. Nodes can also be deleting using the same process. If a node is deleted, the lines that are connected to this node will also be deleted.
3.4 Adding a Member in the Truss 30 A member of the truss can be added to the truss by adding new lines in the Truss Designer. A new line can only be created between two nodes. Open the properties of the truss by clicking Properties in the MWF Truss when you have the truss selected in your project. In the Truss Designer, hover over the first node that will connect the line and left-click. Hover over the second node and right-click with your mouse to create the line. A new line representing a member will be created. Make sure you 'double-click' the newly created line to give a proper representation of its use in the Physical Members Settings. 3.5 Adding a new Node To create lines (and subsequently elements) you will need first to create the nodes (or points) that will represent the intersection or end of the element. Two types of nodes can be created: On Member and Off Member.
3.5.1 Adding On Member Nodes 31 In the Truss Designer interface, select the option On Member Point under Element Creation. Click a line that will be the host of the new node. The areas L1 and L2 will show the node numbers that represents the limits of this line. Select a node in this line that will serve as reference for the new node. Tip: An On Member Point can also be created outside the limits of the host line, but in its same direction.
Add the value for the horizontal or vertical distance from the reference node. In this example, the new node will be 5 feet distant from the reference node (6), measured horizontally. 32 Once you click the option for orientation - Horizontal or Vertical - the new node will be created. 3.5.2 Adding Off Member Nodes To add an off member node you will use the option Off Member Point under Element Creation. Add true coordinate values and click Coord Node to have the new point created. Tip: You can pick an existent node and use its coordinate values as a reference for the creation of the new one.
33 You can also create a new node using coordinates relative to existent nodes. For that, pick an existing node and insert the values for the new node relative to the existent one. Click the option OS Node to create the node. 4. Tools Menu The commands under the Tools menu allow you to change the supports associated to the truss instance. It also allows the creation of "Piggyback" and "Scissor" trusses. 4.1 Add/Remove Supports Support locations will be taken in consideration once creating the truss webbing or when utilizing the engineering capabilities of MWF Advanced. Select a truss envelope or a truss instance and click the command Add/Remove Supports to modify the supports assigned to a truss envelope. Click Add in the Add/Remove Supports dialog box. Then, select the supports to be added and click Finish on the top-right of the drawing area.
Click OK on the following dialog box(s) and click Close to finish the command. 34 A symbol representing the added truss support will show up in the truss representation once the Truss Designer is opened. To remove a support follow the previous steps using now the option Remove in the Add/Remove Supports dialog box. 4.2 Update Supports This command will automatically check if any bearing wall or beam was added or deleted under the truss and update the truss instance with the proper supports.
4.3 Split Cap 35 The Split Cap command is used to create "piggyback" trusses. Start by selecting the truss envelope to be modified and click the command Split Cap under Edit Instance. The Truss Split Cap dialog box will open so you can fill in the values for Height of the lower truss and Gap between the trusses. Check the option Stub Cap Trusses to recess the bottom chord at a given value. You can apply these options to other trusses in the same group by checking the option Apply to all instances of the same group type or uncheck it to modify only a single truss instance. Stub Cap Trusses option checked. 4.4 Scissor The Scissor command is used to create "scissor" trusses. Start by selecting the truss envelope to be modified and click the command Scissor under Edit Instance. The Truss Scissor dialog box will open to fill in the value for Elevation.
36 Once again, you can apply these options to other trusses in the same group by checking the option Apply to all instances of the same group type or uncheck it to modify only a single truss instance. 5. Edit Single This command will allow you to edit a single truss without modifying the group. Select the truss you wish to modify and click the command Edit Single. This will open the Truss Designer. You can then modify the truss using the designer and you also have the option to change the truss properties by clicking Settings. This will open the Truss Designer Settings window, where you can modify the Presets. 6. Input / Output 6.1.1 BOM Report This tool allows users to automatically generate a Build of Materials Report (.csv) The table will output the values like profile type (family type), length, quantity and weight.
37 After clicking BOM Report you can select one truss to create the report. An additional window will pop up to label the members By Schedule Label or By Label. By Schedule Label will label each member of the truss according to Revit schedules and give it an alpha numeric name according to quantity. By Label will label each member alphanumerically according to the nodes at each end of the member. Both instances can be shown in the above example. After selecting the Label Method, you will be prompted to browse to a location where you want the file (.csv) to be saved. The new file will be created in the selected folder. 7. Truss Engineering These upgrades to the MWF Pro Series allow engineers and estimators to engineer and determine optimal elements for your project. Virtually any shape is supported and MWF s truss engineeering interface supports both AISI-2012 and ASCE 7-10 codes. Our catalogue of engineered members inlcudes most standard members sizes and most popular light gauge steel manufacturers catalogues on the market.
7.1 Engineering Presets 38 In the General tab under Settings there is an option to check off Engineering Only. When selected, any members which cannot be engineered will be removed from the Member Sizes or Pick list. In the Member Sizes tab, you are also given the option to Send Top, Move Up/Down, Delete/Add, and Enable/Disable. This allows you to create a custom Pick List which the designer will run through when engineering the truss. Half and a Third lateral bracings can also be applied to the Webbing and Heels.
39 In the Engineering section, you can input the Top and Bottom Chord loads to be applied as well as the Spacing for the line load. You are also given the option to change Top or Bottom Chord Spacing to Sheathed or Purlin and are able to adjust the spacing for the Purlin type. 7.1.1 General The General tab details the Building Code used. At this time only AISI 2012 is supported. You are given the option to Separate the Top and Bottom Chord or keep them Whole. Bump Chord on Material Failure will increase the member size of the Top and Bottom Chord upon material failure. There is also the option to change CSI Limits, choose if the connections are to be Rigid/Pinned or Fully Rigid, and change the Screw Category to #10, #12, or ¼.
7.1.2 Deflection 40 The Deflection tab allows you to input deflection limits for Live Load, Total Load Cantilever, Overhang, and Webs. By default these values are set to -1, which disables any deflection limits. 7.1.3 Wind The Wind tab allows users to customize the Wind Load Settings or turn off the Wind Load completely by unselecting Wind Load Settings. The Roof Pitch, Mean Roof Height, Max. and Min. Plan Dimension, Wind Speed, and the Topographical Factor can be customized and by default are set to the above values. Left and Right Web determine which ends are exposed to wind. Exposure Category, Building Classification, and Roof Type can also be customized according the code ASCE 7-10. You are also given the option to include Components and Cladding (C&C) or strictly keep it an MWFRS. 7.1.4 Snow The Snow tab allows users to customize the Snow Load Settings or turn off the Snow Load completely by unselecting Apply Snow Loads. The Pitch, Ground Snow Load, Thermal Factor (Ct), and Distance from Eave to Ridge (W) can be customized and by default are set to the shown values.
41 Risk Category, Terrain Category, and Exposure can also be customized according the code ASCE 7-10. 7.1.5 Combinations The Combinations window shows the possible different Load Combinations taken when performing analysis according to ASCE 7-10. 7.2 Truss Analysis and Design In the Truss Designer, the Engineering tab enables you to Display Loads and Analyse and Design the truss. Once analysis has passed, the structural Diagrams can be viewed and will be shown in more detail later in the tutorial. When no analysis has been done, Not Analysed will appear in the window header.
42 By default, the members first used to analyse will be the ones at the top of the Pick List. Changing the members sizes can be done by adjusting the Pick List, or by double clicking a line and opening the Line Options window. To begin analysing the truss, select Analyse. If the truss has failed, Analysis: Failed will display in the designer header. To view specifically which members have failed, switch to the Analysis View or the Physical and Analysis View. Failed members will be highlighted in red. After a failed analysis, select Design. The designer will then go down the Pick List automatically analyzing larger sizes to replace the failed members. Once Design is complete, Analysis: Passed will display in the header.
7.2.1 Node Options 43 Wind and Snow type loads can be created for a group of trusses in Engineering Presets. In the Truss Designer, you have the option to create point loads specific to a single truss. Double clicking a node will open the Node Options window, where you can input negative and positive Horizontal and Vertical loads. After selecting OK, a purple circle will be placed around the node indicating that it has point loads. Point loads can be placed at any point on a member as long as there is a node in the desired location. You can also create or change supports within the designer using the Node Options. After placing a node, select Has Support. The Width of the support and the Alignment of the node can both be customized. After selecting OK a support is indicated by the highlighted symbol.
7.2.2 Display Loads 44 Selecting Display Loads will bring the truss into the Analysis View. A dialogue box will pop up allowing you to select multiple types of distributed and point loads. As shown above, the Dead loads are shown in red, the Live are shown in green, and the Ice Dam Load is shown in white.
7.2.3 Diagrams 45 The Diagrams option displays multiple analysis diagrams under different load combinations for Moment, Deflection, Shear, Axial, and CSI. As shown in the above example, when Envelope is selected it shows all the possible bending moment diagrams. 7.3 Reports After a passed truss analysis, select Reports to produce a Fabrication Drawing, Engineering Drawing, and Detailed Engineering Drawing.
46 The Fabrication Drawing provides the number of screws required for a specific location, the type, and an overall Total Screw Count. It also lists the separate members, their Length and Material. The Engineering Drawing provides a Reaction Table detailing the support reactions, as well as a Member Forces Summary and a Load Summary based on the loads and settings chosen in the Engineering Presets.
47 The Detailed Engineering Drawing provides similar tables, but details the reactions of each member and joint, as seen in the examples below.
7.4 Manage 48 The Manage tab groups identical instances and allows you to select any truss or envelope in the project. You can view if the truss has been created, analyzed, and if it supports any other trusses. Additionally, selecting any of the options from Create to Edit will access the Presets and open the Truss Designer. 8. Floor Trusses MWF Pro Floor works cohesively with the truss module to create and design floor trusses. The method to create the floor trusses is nearly identical to framing a floor, with the only change lying in the Properties tab. Select a floor template and hit Create under the MWF Floor tab. Two default light gauge steel templates are available. Select the desired orientation as Back to Back or Wall and click Create.
49 Identical to floor framing, the panel name and direction arrow will appear. To change the orientation of the trusses rotate the direction arrow. To start creation, select either and click Properties. In Properties under Member Properties, select Joists. This will open the Presets window, which is similar in every detail but now includes Spacing, Truss Depth, and the Truss Category is now switched to Floor. The method to customize Presets however is exactly the same as a roof truss. Note: Always have Method set to Fixed Spacing. End Joists (Trusses) under Member Properties can also be customized and once again have the same Presets window. Tip: If the end trusses are identical to the main trusses, save the Joist Presets to an XML file and load them in the End Joist settings. This will save the time of manually having to re-input the Presets.
8.1 Floor Engineering 50 The Engineering section is also identical. When a floor is selected for creation, the Floor option will automatically be selected for the Engineering and Deflection settings. After truss creation, you can return to the Pro Truss tab to use the Truss Designer. Select a truss and click Edit Single to open the Truss Designer. Before Analysis or Design supports have to be manually added. Simply double click on the supporting nodes to open the Node Options. Once supports are added, methods to engineer floor trusses are identical to roofs. Note: Settings can always be adjusted in the Pro Truss Presets tab or the Truss Designer after the floor trusses have been created.
9. Truss Profile Approach 51