Structural Mechanics for dummies

What is Structural Mechanics?

From a fixed point of view, structural mechanics is the science that describes and predicts the conditions under which structures remain or should remain in a state of rest under the influence of different loads or forces. This means that the structure must not collapse.

Structural design

Structural design is the process of choosing the right system or frame device to support the shape or form and prevent its destruction. The support system is called a structure. The structure consists of one part or separate parts, called structural elements. Structural elements are parts of the frame that help support the structure.

Structural classification

Structures are classified according their use and need:

• Domestic and residential - Dwelling houses, hotels, motels and guest houses

• Offices and commercial - Banks, shopping centres and department stores

• Institutional and exhibitions - Hospitals, colleges and universities, museums, art galleries Warehouses, factories, power stations 

• Industrial Other structures - Bridges, towers, water towers, electric towers, offshore structures, telescopes, etc.

The purpose of a structure

The primary purpose of a structure is to transmit the load from the application point to the support center and, finally, through the foundations to the ground. objectives to be met within the constraints imposed by the client's brief, which will inevitably urge the low initial cost and low maintenance costs and vague can define functional requirements of the project. Therefore, the design process begins with an assessment of customer needs through co-operation with members of the design team project.

Project design team

The project design team normally consists of the following:

• Architectural engineers are involved in the production of structural planning models and / or computer simulations to meet the needs of customers and employees to control the project consultant engineer until the completion of the project

• Consultants execute the detailed design, supply tender documents and construction drawings, decides the material, the type of structure and shape, and design methods that will be used; supervise, inspect and approve the materials, fabrication and construction activities and check construction activity. This includes electrical structures, mechanical. heating and ventilation engineers, and quantity surveyors Surveyors and building. In some cases, the builder or contractor can also be referenced in this level.

• Builder or contractors carry out all development activities, such as earthworks, foundations, manufacturing of structural elements and frame buildings, walls, bracing, finishing, installation of equipment and services (heating and ventilation systems, and others).

The design process

The structural design itself is a combination of art and science in that it is the creation of a structural form that will accommodate the often conflicting aspects of cost, function, services and aesthetics, and be capable of being quantified to produce dimensioned details for the purpose of erection.

There are, therefore, two distinct stages in the design process as follows:

Stage 1: conceptual design and planning stage

Structural engineers draw on their experience, intuition and knowledge to make an imaginative choice of a preliminary scheme in terms of layout, materials and erection methods, based on the most economical structural form, construction and erection methods, and materials which could be used. They will examine the structural site and ensure that it is suitable for the project. The behavior of the supporting ground under the load applied by the structure should be fully investigated. Knowledge of the interaction of soil and structure is required so that the most suitable structural form and type of foundations can be chosen.

Stage 2: the detailed design stage

In this stage, the chosen scheme is subjected to detailed analysis based on the principles of structural mechanics. The resulting scheme must be consistent with the engineer's basic aim to provide a structure that satisfies the criteria! of safety and serviceability at reasonable cost. This stage of design includes:

1. idealization of the structure and any complex parts of the structure by means of mathematical models for the analysis and design process;
2. estimation of all relevant loads, and any realistic combination of loads, that produce the most critical effects on the individual elements of thestructure and on the structure as a whole;
3. design of all the structural elements, such as foundations, walls, structural frames and connections:
4. preparation of final detailed drawings, materials lists, specifications for both fabrication and construction activities, bills of quantities and tender documents

The fabrication and construction of the structure are the processes of making the individual elements of precast concrete or steel frame buildings. Structural design aims include technical, architectural and financial concepts. The primary technical aim is that the structural engineer must ensure. that the structure as a whole and its individual elements are strong enough to withstand the most critical action of the applied loads or combination of loads to which the structure will be subjected throughout its design life.

There should be no possibility of progressive collapse of the structure or its individual elements under normal and/or accidental loadings. Structural engineers need to ensure that they are familiar with issues such as the strength of material used and generate a greater consideration of serviceability, including dynamic structural response, as part of the development of a safe structural form. The design engineer also aims to increase the efficiency of the structure, and to ensure adequate resistance to fire, overturning, corrosion, etc. Financial aims look to the achievement of a minimum overall cost of the structure by striking a balance between the costs of materials, labour and the method of erection.