|
|
|
Foundation ::
Engineering Applications ::
VLOADS
|
VLOADS
Launch Vehicle Loads Analysis For Preliminary Design
|
 |
|
SOURCE CODE AVAILABLE
|
|
The VLOADS program calculates launch vehicles in-flight structural loads for preliminary design. The program may also be used to calculate structural loads for upper stages and planetary transfer vehicles. Launch vehicle information and input data such as aerodynamic coefficients, mass properties, propellants, engine thrusts, and performance data are compiled and analyzed by VLOADS to produce distributed shear loads, bending moments, axial forces, and vehicle line loads as a function of X-station along the vehicle s length. Translational accelerations and interface loads, if the launch vehicle has boosters or wings, are also computed.
An attractive feature of the VLOADS program is that its Visual Basic for Applications (VBA) source code has been integrated into an easy-to-use Microsoft Excel user interface. The VLOADS program uses the individual worksheets in its Excel workbook as input and output data files, in a manner that is similar to the way more traditional FORTRAN and BASIC programs have used text files for input and output files. Because VLOADS has been integrated into an Excel workbook, it is much easier for the user to edit the input data, to run the program, and to view the results than in more traditional FORTRAN and BASIC engineering codes.
The major strength of this program is that it enables quick turn-around analysis of structural loads for launch vehicles during the preliminary design phase of the vehicle's developmental life cycle. This represents an alternative to the time-consuming and expensive chore of developing finite element models for detailed loads analysis. In preliminary design, much remains unknown about the detailed configuration to which the launch vehicle will mature.
For preliminary design, it becomes necessary to make some simplifying assumptions to initiate the process by which structural loads may be calculated for preliminary structural design and analysis. VLOADS is a two degree-of-freedom program that calculates the axial force distribution, shear force distribution, and axial bending moment distribution along the launch vehicle's length. It essentially treats the launch vehicle as a rigid beam and vibrational effects are not considered in the analysis. The Method of Sections is employed to determine the shear, moment, and axial load at any predetermined X-station number. Rotational acceleration in the pitch plane is assumed equal to zero, so that the sum of the pitch moment equals zero.
VLOADS carries the NASA case number MFS-27332. It was originally released as part of the NASA COSMIC collection.
|
|
More software from National Technology Transfer Center
|
|
|
|
|
|
|
Open Channel Software runs entirely on Open Source Software. We return
value to the Software community in the form of
services and original software. Most of our
content is currently available as source code, with the
copyright owned by the original author, All
Rights Reserved. Everything else is Copyright
©2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Open Channel Software.
View our privacy statement.
Contact webmaster at openchannelsoftware dot org with questions.
|
|
|
