Graduation design opening report

1. Name of the project:

Development of reinforced concrete multi-layer and multi-span frame software

2. Project research background:

The structural program to be written is the design of the concrete frame structure, which refers to various houses and their associated structures. The building structure is a plane or space system in the building that can be subjected to a function by a number of components, that is, units constituting the structure such as beams, plates, columns, and the like.

The calculation example uses the latest "Concrete Structure Design Code" GB50010-2003 issued by the Ministry of Construction. Compared with the original concrete structure design specification GBJ10-89, the new content accounts for about 15%, and the major revision accounts for about 35%. The part that maintains and basically maintains the original specification content accounts for about 50%. The specification comprehensively summarizes the practical experience since the original specification was issued, and draws on foreign advanced standard technology.

3. Project research significance:

In the building, the structure is an important part of providing buildings with safe, reliable, durable, energy-saving materials and meeting the building functions. It is closely related to the industrialization level of building materials, products and construction, and develops new technologies. New materials have an important role in promoting mechanization and automation.

There are many mathematical formulas involved in structural calculations, and the specifications and standards involved are very fragmentary. And the amount of calculation is very large. In recent years, with the further development of the economy, the concentration of urban population, the tight land use and the fierce competition of commercial competition have further complicated the complexity of housing design, and many high-rise buildings have been continuously built. These buildings objectively require the auxiliary design of computer programs, both in terms of time and labor. In this way, the development of structural software is particularly important.

Whether the structural design of a building is reasonable depends mainly on the structural system, structural arrangement, cross-sectional dimensions of the components, material strength grades, and whether the main structural structure is reasonable. These problems have been solved correctly. The calculation of structural calculations and construction drawings is another hard work of specific programming. Therefore, the hand calculation method originally used in schools will be applied to the specific program code. Not only how to use the structural knowledge learned to design the practice, but also how to implement these practices in code.

4. Overview of literature research

Some content is the same in different types of structural design. The key to designing a frame structure is to reduce missing items and reduce errors. The same is true for computers.

Uniform Standard for Building Structure Design This standard is a basic principle for rationally unifying the structural design of various materials. It is to formulate structural load specifications for industrial and civil buildings, steel structures, thin-walled steel structures, concrete structures, masonry structures, and wood structures. Such design specifications and guidelines for designing foundations such as foundations and seismic buildings shall be formulated in accordance with the requirements of this standard. When formulating other civil engineering structural design specifications, the principles specified in this standard may be referred to. This standard applies to the entire structure of the building, as well as the components and foundations that make up the structure; applies to the stage of use of the structure, as well as the construction phase of the fabrication, transportation and installation of structural members. This standard introduces the modern structural reliability design theory, and uses the limit state design method based on the probability theory to analyze and determine that all the factors affecting the reliability of the structure are regarded as random variables, so that the design concepts and methods are based on statistical mathematics. On the basis of, and to measure the reliability of the structure based on the probability of failure determined mainly by statistical analysis, it belongs to the “probability design method”, which is an important evolution of design thinking. This is also the general trend of the development of engineering structure design methods in the contemporary international, and China's use of the probability limit state design method in the design specifications is by far the most widely used country.

The common effects of structural effects are:

1. Internal force.

An axial force, that is, a normal tensile force or pressure on a positive section of a structure or member caused by an action;

Shear force, ie the tangential force on a section of a structure or component caused by an action;

The bending moment, that is, the internal moment on a section of the structure or member caused by the action;

Torque, the force moment formed by the shear force on a section of a structure or component caused by an action.

2. stress. Such as normal stress, shear stress, principal stress, etc.

3. Displacement. A change in the position or orientation of a line in a structure or component caused by an action.

4. Deflection. A point on the axis or mid-surface of the component is displaced perpendicular to the axis or mid-plane in the plane of the bending action.

5. Deformation. The relative displacement between points in a structure or component caused by an action. The deformation is divided into elastic deformation and plastic deformation.

6. Strain: such as line strain, shear strain and main strain.

Limit state The entire structure or part of a structure that exceeds a particular state cannot meet a functional requirement specified by the design. This particular state is called the limit state of the function. The limit states can be divided into two categories:

1. Carrying capacity limit state. The structural or structural member reaches the maximum load carrying capacity or reaches a limit state that is unsuitable for continued bearing deformation:

Part of the entire structure or structure is out of balance as a rigid body;

Structural members or wires are destroyed by the strength of the material being exceeded, or are not suitable for continued bearing due to excessive plastic deformation; the structure is transformed into a maneuvering system;

Structural or structural members lose stability.

2. Normal use limit state. The structural or structural member reaches a limit state using a certain limit that is functionally permissible. When one of the following states occurs, the normal use limit state is considered to be exceeded:

Affecting the deformation of normal use or appearance;

Local damage affecting normal use or durability;

Vibrations that affect normal use; other specific conditions that affect normal use.

The basic task of structural design is to choose a reasonable balance between the reliability of the structure and the economy, and strive to achieve the predetermined safety under the specified conditions and within the specified service life at the lowest cost. Functional requirements such as suitability and durability. To achieve this goal, people have adopted a variety of design methods. From a modern point of view, it can be divided into two categories: fixed value design and probability design.

1. Fixed value design method. The main factors affecting structural reliability are regarded as non-random variables, and the design method of structural reliability is determined by empirically determined safety factor, namely deterministic method. This method requires that the load effect S of the structure should not be greater than the structural resistance R in any case, ie S ≤ R. Before the mid-1970s, this method was mainly used in China and abroad.

2. Probability design method: The main factors affecting the structural reliability are regarded as random variables, and the failure probability or reliability index determined by statistics is used to measure the knot.

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