> For the complete documentation index, see [llms.txt](https://docs.paragontruss.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.paragontruss.com/design/reference/display-forces.md). # Display Forces The **Display Forces** menu lets you overlay the analysis results from a single load case directly onto the truss in the scene. Each option below toggles a distinct set of visuals on the [Analog Model](/design/explanation/analysis/analog-modeling.md). ## Accessing Display Forces Display Forces is only available after a [Detailed Analysis](/design/how-to/general/run-and-view-component-analysis.md#run-a-detailed-analysis-to-access-force-visuals) has been run and a specific load case has been selected. The button is found in the `Analysis and History` subpanel. {% hint style="info" %} **Note** If the `Display Forces` button is disabled, either no load case is selected or the active analysis has not been saved. Run a Detailed Analysis and select a load case to enable it. {% endhint %} Selecting a force from the menu turns the analog model on automatically and re-loads the analysis results so the visuals can be drawn. Each option can be toggled on or off independently — you can show several at the same time. ## What Each Option Shows ### Reading the Labels Most Display Forces options draw both an arrow and a numeric label. The label format depends on the option: | Option | Label format | Units | | ------------------------------------ | --------------------------------------------------- | -------------- | | Member Deflection Curves | (no label — visual only) | — | | Link Deflection Curves | single peak value | in. | | Force Proof | `Fx,Fy` per link end; moment as a separate label | lbs and lb-in. | | Bearing Reactions | `Fx,Fy` per bearing; moment as a separate label | lbs and lb-in. | | Link End Forces Axial and Transverse | two separate labels (axial and transverse) | lbs | | Link End Forces — Global | `Fx,Fy` per link end; moment as a separate label | lbs and lb-in. | | Moment Curves | single peak value | lb-in. | | Shear Curves | single peak value | lbs | | Plating Forces | `Fx,Fy` per plate force; moment as a separate label | lbs and lb-in. | For options whose label shows `Fx,Fy`, the values are the **global** X and Y components of the force the arrow represents. A negative value means the component points in the negative global direction — it does **not** by itself mean compression. Compression versus tension is conveyed by the arrow's color, not by the sign of the label. Arrow lengths for force visuals are scaled by a fixed pounds-to-inches factor, so a longer arrow always means a larger force across the scene. Very small forces (and moments below roughly 0.5 lb-in.) are not drawn. ### Member Deflection Curves (in.) Draws an exaggerated, animated yellow spline along each member showing the shape it deflects into under the selected load case. The spline smoothly follows the member from its undeflected position to its deflected shape, giving you an at-a-glance view of both the direction and relative magnitude of bending. Use this option to confirm that members are deflecting the way you expect (e.g. top chords sagging between panel points, cantilevers deflecting downward at the tip).
### Link Deflection Curves Draws a green curve along each analog link representing the same deflection data, labeled with the peak deflection value in inches next to the link. Unlike **Member Deflection Curves**, the link-level curve is static and is labeled, so it is useful when you want to read the numeric deflection on a specific link rather than visually compare deflection across the whole component.
### Force Proof Places force and moment arrows at every analog joint that show how all of the forces and moments meeting at that joint sum to the joint's reaction. The arrows are arranged tip-to-tail around the joint — when force equilibrium is satisfied at the joint, the chain closes back on itself (the tip of the last arrow lands on the tail of the first). A joint with only a moment arrow and no force chain means the joint has a net moment but no net force. * **Yellow arrows** indicate tension (the member is pulling away from the joint). * **Blue arrows** indicate compression (the member is pushing into the joint). * A curved arrow at the joint indicates the resultant moment, when present. Force Proof draws results per link end, so the same web appears once near each of its two joints. For a member carrying mostly axial load, the two labels are approximately equal in magnitude but opposite in sign — the force vector points away from each joint, which is opposite directions in the global frame. For example, Web 3‑16 might read `768,-640` near joint 3 and `-801,667` near joint 16; the small differences (768 vs. 801, 640 vs. 667) come from any transverse load the web is also carrying along its length. If the cluster of arrows and labels at a joint is hard to read, switch to **Link End Forces — Global**, which shows the same `Fx,Fy` values but draws each arrow on the member itself rather than stacked tip-to-tail around the joint.
{% hint style="info" %} **Note** Force Proof is hidden while any analog link is selected so that the selection-specific visuals are not obscured. Click in an empty area of the scene to deselect and bring the Force Proof visuals back. {% endhint %} ### Bearing Reactions (lbs) Draws a single force arrow at each bearing showing the net reaction the bearing applies back to the truss for the selected load case. The arrow's direction and length represent the resultant of the X and Y reaction components, and a label shows the global component values in pounds in the form `Fx,Fy` (e.g. `0,1450` for a 1,450 lb vertical reaction). A curved arrow with its own `lb-in.` label is drawn when the bearing also resists a moment. Use this option to quickly see how much load each bearing is picking up under a given load case and in which direction the reaction acts.
### Link End Forces Axial and Transverse (lbs, lb-in.) At each end of every analog link, draws a magenta L-shaped box that decomposes the link's end force into its **axial** component (along the link) and **transverse** component (perpendicular to the link). The two legs of the box are labeled with their magnitudes in pounds, in the link's local reference frame. For the axial label, a **negative value means compression** (the member is being pushed in along its own axis) and a **positive value means tension**. The transverse label's sign indicates the direction of the perpendicular component in the link's local frame. This is the option to choose when you want to understand bending versus axial behavior of a specific member — for example, to see how much of a chord's end force is acting along the member versus pushing the member sideways.
### Link End Forces — Global (lbs, lb-in.) At each end of every analog link, draws a single force arrow in the **global** (component) reference frame. The arrow points in the direction the force acts on the joint, with a label showing the global X and Y force components in pounds in the form `Fx,Fy`. Yellow indicates tension, blue indicates compression, and a curved arrow with its own `lb-in.` label shows the moment at the link end when present. This option shows the same per-link-end data that **Force Proof** uses, but the arrows are drawn on the member itself rather than rearranged tip-to-tail around the joint. It is usually the easier of the two to read when you just want to know each member's end force.
### Moment Curves Draws an orange curve along each analog link representing the bending moment distribution along that link. The peak moment along the curve is labeled in pound-inches next to the link. Members with significant bending will show a pronounced bow in the curve; members carrying mostly axial load will show a nearly flat curve close to the link.
### Plating Forces (lbs, lb-in.) At each joint covered by a plate pair, draws force arrows representing how each member's end force is resisted by the plates. Each arrow is labeled with its global X and Y components in the form `Fx,Fy`; a separate `lb-in.` label is shown for any plate moment. * **Yellow** — the plate is resisting a tension force. * **Blue** — the plate is resisting a compression force. * **Green** — the force is the merged resultant for plates that act together at a joint. * A curved arrow shows the moment carried by the plate at the joint, when present. Use this option to see the load path through each plated joint and to identify joints where plates are carrying unusually large forces or moments.
### Shear Curves Draws a teal curve along each analog link representing the shear force distribution along the link. The peak shear value is labeled in pounds next to the link. Steep changes in the shear curve indicate locations along the link where transverse loads are introduced.
## Combining Options Multiple options can be enabled at once. Common combinations: * **Moment Curves + Shear Curves** — review bending and shear behavior of a member side by side.
* **Member Deflection Curves + Bearing Reactions** — confirm that the deflected shape matches the loading and support pattern.
* **Link End Forces (Global) + Plating Forces** — trace the load path from member ends into the plates at each joint.
{% hint style="success" %} **Tip** If the scene becomes cluttered with overlapping arrows and labels, toggle off the options you are not actively comparing. Each option is independent, so you can leave one or two enabled and cycle through the others as needed. {% endhint %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.paragontruss.com/design/reference/display-forces.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.