Computer Applications - CHIMNEY

CHIMNEY is a computer software tailored for the design and documentation of the steel structure in chimneys and similar structures with rotational symmetry, such as towers. Alternatively, the program may be used for checking the design of a structure with given dimensions.

CHIMNEY has been used for practical design purposes since 1980 and has been gradually improved and extended. The program has been used for the design or checking of close to 1 000 different steel chimneys, towers, wind turbine towers etc.

CHIMNEY permits very general conditions, for instance, conical shell sections (see figure), partly enclosed structure, varying material properties in different parts of the structure, side bracing, etc.

An extensive data library is included, for instance, material data, normally available plate dimensions, wind-loading data and so on. These data may be substituted by the user's own data.

Much effort has been spent to make the program user-friendly, so that a normal chimney may be defined in a simple way, while allowing special conditions required for complicated cases.

CHIMNEY considers the following structural components:
1.Structural shell and welds
2.Anchor bolts
3.Base details, that is, base flange, stiffeners and supporting flange, allowing four different alternatives for the design (see figure for three of those)
4.Ovalling rings
5.Helical strakes to reduce vortex shedding
6.Flanged erection splices

CHIMNEY produces the following documents with results, in English or Swedish:
1.A summary of the results of the structural analysis
2.A complete and self-explanatory report of the structural analysis
3.A steel specification list with a compilation of estimate costs
4.A program for inspection and testing of welds
5.Drawings in A4 format:
a) View, general requirements
b) Anchor bolts
c) Base details
d) Helical strakes
e) Ovalling rings
f) Ladder
g) Flanged erection splices

A separate procedure is connected to CHIMNEY for the design of required reinforcement at openings in the shell for connecting ducts, entering doors etc.

The structural analysis includes load-carrying capacity for gust wind, fatigue strength from vortex shedding and gust wind, and deflections. Loading conditions and structural models have been adapted to the rules in BSV 97, which in many respects are similar to those of the current CEN standard.
The CHIMNEY program is presented in a User's Manual with description of structural models, possible input data and two fully worked design examples.

CHIMNEY is available for use through StBK Stålbyggnadskontroll.