Examples

These are not pictures of the software. Each one is the figure itself — the same payload, drawn by the same renderer, that a report exported from Visual Dynamics carries. Drag to rotate, scroll to zoom.

The first three follow one job: a modal survey of a rectangular plate — the record as it was measured, the plant computed from it, and the finite element model it was run against. The last is a finite element model built from scratch, from the planes a shared test article is made of.

The measured record

Time data from the survey, one channel per station receding into the stage — six of the two hundred and twenty accelerometer records, drag to turn it.

The measured plant

The frequency response functions computed from those records, ten of twenty-two. Overlaid on a single axis they would be a band; given depth, each channel keeps its own resonances.

Finite element modes

The first six elastic modes of the plate, from a model of 169 nodes and 144 elements. Choose one from the list and it animates; drag to turn it. The six rigid-body modes a free-free solution also produces are left out — they show the whole plate moving and say nothing about how it bends.

A model from planes: the BARC

The BARC — Box Assembly with Removable Component — is a small bolted aluminum structure the structural dynamics community shares as a common test article, its solid model, test data and finite element models shared on the SEM Dynamic Substructuring Focus Group wiki. Here it is built the way a simple plate model is built in Visual Dynamics: each part as the planes it is made of, each given its material and thickness, each bolt a rigid tie from the elements its washer covers to the part below, and Solve Modes.

The first eight elastic modes of the model, drawn from a quarter-inch mesh of 1,445 nodes. Choose one from the list and it animates; drag to turn it. The model was checked against the finite element models shared on the wiki. The whole workflow, from the planes to these modes, and the project itself, solved, to open in the app.

The BARC again, from bricks

The same structure built from solid bricks, the higher-fidelity model: each part as the boxes it is made of, the channels' feet joined to the box over their whole footprint, the beam resting on the channels and tied to them over each washer, and each bolt a point mass at its head. The removable component, the two channels and the beam, is a model of its own beside it.

The first eight elastic modes of the assembly, drawn from a quarter-inch mesh of 3,198 nodes. Choose one from the list and it animates; drag to turn it. Meshed at an eighth of an inch, its first ten elastic modes land 1 to 4 percent above the ones measured on the BARC and shared on the wiki, and its mode shapes follow the shared finite element model's in order. How it is built, and both models, solved, to open in the app.

A model from blocks: the four-unit frame

The four-unit frame is a small aluminum ladder the structural dynamics community shares as a test article for substructuring, with two rectangular wings that screw across it; its solid models, finite element models and test data are shared on the SEM Dynamic Substructuring Focus Group wiki. A half-inch bar spanning a hundred-millimeter window is not a beam and not a plate, so this one is built from solids: each part as the blocks it is made of, meshed into bricks, the insert holes cut from them, the fillets kept, each screw a rigid tie from the bricks its washer covers to the frame under it, and Solve Modes.

The first eight elastic modes of the frame with its thick wing, drawn as the skin of a mesh of bricks. Choose one from the list and it animates; drag to turn it. The frame alone lands within a few percent of the frames that were measured, and the brick element was checked against the finite element model shared on the wiki: solved here, mesh for mesh, its modes agree with MSC Nastran's to a tenth of a percent. The whole workflow, from the blocks to these modes, and the projects themselves, solved, to open in the app.

About these figures

They are drawn by the report renderer rather than by anything written for this website, which is deliberate: what you turn here is what a report carries, and a second drawing path built for the web would be free to drift from the first.

They are, however, smaller than a report's: a handful of channels rather than every one, so the page arrives quickly and turns smoothly. A report is held to a stricter rule — it must not reduce the data it reports, since a thinned figure cannot answer a question asked of it later — and wherever a figure has been thinned at all it says so, in a note under its own caption. Download the application to see the whole of it.