DynaSpeed : a compact Windows solution for the professional engineer

Structure

DynaSpeed is a conceptual design tool for the pre-dimensioning and the dimensioning of mechanical systems. Those sytems are defined by several masses coupled with spring/dampers attached to a rigid or flexible basis. The non-linearities are given by : large displacements, large rotations, stiffness curves, modal damping. An integrated solver compute eigenmodes, modal analysis, shocks, transient analysis, sinus and random spectra, static loads ... A user-friendly C++ /OpenGL graphical interface is included for the creation of the model and the post-treatment (curves, displacements, animation, bitmap, report).

The rigid bodies can be homogeneous or nonhomogenous spheres, cylinders and bricks. The elastic plates can be used as flexible basis.

Loads

These structures are loaded by the gravitational forces, static forces, dynamic forces and basis accelerations.

There are 6 kinds of applicable dynamic forces and basis accelerations:

- harmonic

- half sine pulse

- saw pulse

- random

- given by their Fourier spectrum

- user-defined curves

Analysis

The available kinds of analysis are:

- static analysis

- eigenanalysis of the undeformed system or in the static equilibrium position

- dynamic analysis under dynamic loads, starting or not from the static equilibrium position, performed as:

- transient analysis (step-by-step integration)

- modal analysis (preferably of linear systems - requires eigenanalysis too)

- spectral analysis (based on response spectrums - also requires eigenanalysis)

- response spectrum computation under harmonic excitations.

Responses

The obtained results are:

- time history of absolute and relative responses in displacements (including the static equilibrium position under permanent forces), velocities, accelerations

- time history of forces in springs and dampers

- time history of reactions

- maximum values of the responses

- Fourier transform of the responses

- harmonic response spectrums

- eigenvalues and eigenmodes

Results

All asked results are saved in a binary file that can be studied using the plotting utility (Plotter). This program also permits saving results in Excel importable files, saving and printing images (plots).

The motion and the computed eigenmodes of the analyzed structure can be viewed as animation.

Software

DynaSpeed has an easy-to-use graphical user interface developed in Visual C++ and OpenGL, with on-line help. Its solver and its plotting utility are written in Fortran 90 + Winteracter.

Before any computation the solver program checks the model and the input data to see if anything is ok. If it finds missing or incompatible data a warning or an error message is generated depending on the influence of the found problems. When these prevent the computation to be done correctly the solver halts giving a message in this sense.