# Difference between revisions of "Digital Structures"

This article is about a replacement event for that might not be run at every tournament. Please refer to instructions from your particular tournament before preparing for this event. For the event it replaces, see Boomilever. For a guide to supervising the event, see Digital Structures/Supervising.

Digital Structures is a simulated building event that may replace Boomilever for some tournament formats during the 2021 season. For this event, students will use SkyCiv structural analysis software to design and test (in simulation) a Boomilever that meets construction requirements outlined in the rules. This event was first run at BEARSO Invitational under the name Computilever.

## Event Summary

A sample Boomilever designed in SkyCiv.

The idea of this event is very similar to the Boomilever event it replaces. However, in this event the Testing Wall is defined by a geometric plane, the Mounting Hook is defined by a 3D Pin Support, the sticks of the Boomilever are defined by nodes and members, and the weight from a bucket and sand is simulated with an Area Load.

The geometric plane that defines the Testing Wall is the yz-plane, and the entire Boomilever must lie on its non-negative-x side. The Mounting Hook is a "3D Pin Support" at the origin. The load applied to the Boomilever is in the negative y-direction over a 5.0 cm by 5.0 cm rectangular Area Load defined by its corners with nodes that are called Loading Points.

There are two unknown specifications that are not shared with teams until the competition. These are minimum distance between the Testing Wall and the Loading Point closest to the Testing Wall and the distance from the origin to the Contact Width Lines. The minimum distance between the Testing Wall and the Loading Point closest to the Testing Wall will be 20.0-45.0 cm from the Testing Wall in the positive x-direction. The Contact Width Lines, two imaginary vertical lines parallel to and symmetric about the y-axis, will be 3.0-7.0 cm from the origin in the positive and negative z-directions.

The Contact Depth Line, an imaginary horizontal line parallel to the z-axis, is 20.0 cm (Division B) or 15.0 cm (Division C) from the origin in the negative y-direction. The Boomilever may not touch between the Contact Width Lines or below the Contact Depth Line.

## Software

Main article: SkyCiv

The software used for this event is SkyCiv with the Science Olympiad add-on (available as an add-on within the software). SkyCiv provides the functionality for adding nodes, members, materials, and loads, while The Science Olympiad add-on limits materials to 3 varieties of balsa woods, limits number of times students can test their device to 5 times, checks for construction violations, and submits design files to tournament officials during the competition. Please see the page on SkyCiv for an introduction and tutorial to the software.

## Competition

At the competition, the Event Supervisor will tell students the values determined for minimum distance between the Testing Wall and the Loading Point closest to the Testing Wall and the distance from the origin to the Contact Width Lines. Students will then estimate the load their Boomilever will support (Estimated Load Supported) and have 45 minutes to build and test their Boomilever up to 5 times in SkyCiv. SkyCiv will record construction parameters and calculate the scores for each device.

## Scoring

Scoring for Digital Structures and the Boomilever event are very similar. In both events, score is calculated by dividing a Load Score by the Mass of the Boomilever, where high score wins. The Load Score is the sum of the Load Supported by the Boomilever and the Bonus. This Bonus is 5,000 g only if the Load Supported is 15,000 g.

Score = [Load Supported (g) + Bonus] / Mass of Boomilever (g)

As this is an event in simulation, the Load Supported and Mass of Boomilever are both calculated by SkyCiv using the material properties of the balsa wood type selected by students in their design. The Load Supported is the load (in grams) applied to the Area Load at which any members of the Boomilever experience stress exceeding its parameters.