Computer aided design system of anticorrosive protection of metal constructions of the buildings
Different types of buildings and structures are used in the construction. With the development of building business and machines, there is always a need to improve their properties. For example, product life increase, weight and financial costs reduction, ecological safety and many more. This is also applied to modern technical facilities, subject to high loads and aggressive environmental influences.
Increased durability and protection against corrosion of constructions of industrial buildings and structures is one of the most urgent problems of modern construction and maintenance, both in Russia and all over the world. St. Petersburg hosted the International Conference "Problems of durability of buildings and structures in modern construction" –МКДЗК-07 from October 10 to October 12, 2007. The questionson improving the quality of materials and increase of the product life of structures, both in the process of new construction, as well as their operation and reconstruction were discussed.
Based on the analysis of the submitted data and the reports and speeches made during the debates, the conference noted the course of further scientific and technological progress. One of these areas is the processing of the current СНиП2.03.11-85 taking into account all the scientific and practical achievements in the field of durability and corrosion protection at the same time with the introduction of the section "Reconstruction and restoration of structures operating in aggressive environments."
It should be mentioned that one of the developers of СНиП 2.03.11-85 "Building Regulations. Protection of building structures against corrosion" is Professor Andrey Iovich Golubev, Doctor of Technical Sciences, who was the head of the department of anticorrosion protection of building structures of the Central Scientific-Research and Design Institute of metal building named after Melnikov N.P. for many years. In 2011, he had 100 years anniversary.
Harsh operating conditions of industrial buildings and structures lead to quick failing of building structures. In connection with this, the conditions of operation of structures should be checked thoroughly, the stress - strain state with the corrosion should be determined and predicted better, areas of local hubs should be identified and etc.
To ensure safe operation of buildings and structures, in order to prevent industrial accidents and environmental disasters it is important not only to design the structure thoroughly, but also to conduct a condition survey of the actual state regularly and to recalculate the solidity. At the same time, the changes in the geometry and metallographic properties due to corrosion, degradation and wear during operationshould be taken into account. More attentionshould be paid to anticorrosion protection. It seems appropriate to develop a system of computer-aided design (CAD) of anticorrosion protection. This would facilitate more economical and low cost ways of protection, reducing the time to develop them and better quality of design work.
Solving the task set by the International Conference "Problems of durability of buildings and structures in modern construction" - МКДЗК-07 and before the next All around Russia Conference on problems of durability and anticorrosion protection, I have developed the computer aided design system of anticorrosive protection of metal constructions of the buildings (CAD "Corrosion protection").
For computer-aided design of anticorrosion protection of metal constructions relational database (RDB) and the means for manipulating the data called CAD "Corrosion protection" were developed.
The database is a computer analog of organized information. Database management systems supporting the relational data modelhave taken the greatest application on PCs. The relational model allows us to build a database of relations. A simple table describes the concept of relation. Relational database is a collection of interconnected relations. Relation is a collection of records of the same structure, organized in a logical separate set of data. Relation has only two dimensions and consists of a fixed number of columns and any number of rows. The columns are called attributes or relation fields. Attributes have names - headlines. Each individual record of the relationis called a tuple or a record. In the table, tuples relations have the same structure. This means that individual components of the tuple attributes have the same type and length and occupy the same position in all the tuples of the relation. Each attribute has a name that must be unique in respect.
Relations of RDB are stored independently of each other, and their interaction is set externally and is detected by database management system when manipulating the data or performing other functions of DBMS. The relation between attitudes of RDB is specified via their attributes. The same attribute can belong to multiple relations of RDB, so their relationis established by its values. Thus, the relational approach make it possible to form new relations from the existing ones. At the same time allowed the formation of one relation is possible - the result of several relations - sources.
The relational modelcan be easily adjusted and completed in case new data on the interaction of metal structures and aggressive environment appears.
In this work, CAD "Corrosion protection" is developed in Microsoft Access database. Access is one of the most powerful database management programs. In addition, Access is one of the most convenient and simple applications of Microsoft Office.
Relational database (RDB) has the following data:
- The degree of aggressive influence of gases, solids (salts, aerosols and dust), inorganic and organic liquids and soils on metal constructions and products.
- Ways ofanticorrosion protection of metal structures and productsby means of metallization and paint covering.
- Paint covering systems (group, index, number of coating layers, total thickness of the paint).
- Paint covering materials for the protection of metal structures and products (makeof the paint, the type of binding, the regulatory document, the color and the cost of paint).
- General information on painting materials (outgo of paint, manufacturing address, the source of the information and notes on the use of paints).
- Unified district unit prices to set anticorrosion works, territorial areas and price factors.
- Durability (service life) of protective coatings, depending on the degree of aggressive environmental influences.
The relational model of CAD data "Anticorrosion protection" contains more than thirty of interconnected relations (see Fig. 1). The relational model can be easily adjusted in the case of new data on the interaction of metal structures, products and aggressive environment appear, as it allows supplementing additional data and modifying the structure of applications that use the data.
The chapter from the СНиП 2.03.11-85 "Protection of building structures from corrosion", a collection of 13 unified regional unit prices on building construction and operation СНиП 1У-5-82 "Protection of structures and equipment from corrosion", price lists for paints and other literary sources that are stored in the form of thirty-two relations are data for SRM "Corrosion protection".
To obtain the required information from the RDB CAD "Corrosion protection" it is necessary to determine the source data. They are whatconstructions are made of and location of the constructions, temperature and humidity conditions, the characteristics of solid media (salts, aerosols and dust), the influence of organic, inorganic liquids and soils, pH value, total concentration of sulphates and chlorides, territorial factors and price rates.
The source data describes 17 factors. X1 is the concentration of gas, X2 is the code of the name of the gas, X3 is relative humidity, X4 is the code of the constructionlocation, X5 is the code of the solid media, X6 is pH value, X7 is the total concentration of sulphates and chlorides , X8 is the code of inorganic liquid medium and soil, X9 is the code of organic liquid medium, X10 isthe code of construction material, X11 is average annual air temperature, X12 is pH value of groundwater, X13 is the total concentration of sulphates and chlorides of groundwater, X14 is the code of the soil location, X15 is covering index , X16 is the country code of CIS republics, regions, territories and autonomous republics, X17 is the condition code to the application of price rates.
X1, X2, X3, X4, determineaggressive influence of gaseous medium, X3, X4, X5 - aggressive influence of solid media, X6, X7, X8 - aggressive influence of inorganic liquids, X9 - aggressive influence of organic liquids, X11, X12, X13, X14 - aggressive influence of soil, X10 - metal construction material, X15 - covering index, X16 - the territorial area of the CIS countries, republics, regions, territories and autonomous republics, X17 - price rates.
Means of manipulating the data help to obtain necessary information from RDB relevant to the original data: the degree of aggressive environmental influences, methods of anticorrosion protection systems, coatings, information about painting materials, price for anticorrosive works, the service life of the protective coating, the average annual cost of various options of protective coatings and other necessary information.
CAD "anticorrosion Protection" provides a choice of optimal anticorrosion protection of steel constructions subject to the conditions of their operation, type of corrosive environment and the required resistance of the coating.
Full description of CAD "Anticorrosion protection" is presented in the fourth chapter of the book: Information technology: development priorities: monograph / O.V. Vilchinskaya, I.N. Gataullin, S.O. Golovinovetc. / Editor S.S. Chernova. - Book 5. - Novosibirsk: Publishing House "SIBPRINT", 2010. – 261 pp.
Fig. 1. The relational data model.
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