1.1. Engineering Design Process

Needs are identified then objectives are expressed to meet these needs. Input from:

• Clients
• Governmental regulatory agencies
• Architects, planners, and engineers

In the conceptual stage of the engineering design process, the first step is to identify the needs that a project aims to fulfill. Once the needs are clear, specific objectives are defined to meet those needs. This is a collaborative phase where input is gathered from various stakeholders such as clients who will use the structure, governmental regulatory agencies that have legal requirements, and professionals like architects, planners, and engineers who will be involved in the design and execution of the project.

Think of this stage like planning a big party. First, you ask what your guests need and want. Then you set specific goals, like considering what food they like, how much space you need for everyone, and what rules you need to follow in your venue.

Creative ideas by the engineers. Keep in mind construction aspects. Thorough consideration of expected loads on the structure at all construction stages and during occupancy of the finished structures. Sizing of structural elements for safety and serviceability. Architectural Constraints:

• Simplicity & Duplication
• Fabrication & Construction Procedures. Preliminary design approximate theories of structural analysis are used to minimize time during this phase.

In the preliminary design stage, engineers brainstorm creative ideas and design concepts for the structure. They need to consider practical aspects like how the structure will be built, including the types of materials and methods to be used. Engineers also have to anticipate the loads the structure will experience, both during construction and after completion while accommodating regular occupancy. This entails sizing elements to ensure that they are safe and functioning well. Architectural constraints must also be factored in, which can include features like simplicity in components to ease construction and manufacturing. To save time, engineers may use approximate theories in structural analysis rather than detailed calculations.

Imagine a chef planning a new recipe. They think creatively about the dish they want to make, but they also have to consider what ingredients are available and how to cook them efficiently. They also need to think about how the dish will be plated to look appetizing, which ties back into architectural constraints.

At this stage, all alternatives are presented and all parties involved participate in the selection stage so the final design stage can begin.

In the selection stage, all design alternatives that were developed in the preliminary phase are compiled and presented. This is a collaborative effort, and all stakeholders, including engineers, clients, and possibly regulatory bodies, engage in discussions to evaluate and choose the best design. The aim is to come to a consensus on which option best meets the project requirements before proceeding to the final design stage.

Think of this stage like a group project where members present their ideas for a final presentation. Everyone discusses the pros and cons of each idea before voting on the one they think is best to move forward with.

Loads are determined in greater accuracy than the preliminary stage. All loading combinations are examined in this stage. Structural analysis is carried with greater accuracy than the preliminary stage with the elimination of all approximations. The results are presented in sets of drawings and specifications showing:

• Sizing of Members
• Detailing
• Quality of workmanship
• Design/building codes used.
• Bill of Materials
• Total Cost.

The final design stage is where the design gets refined and detailed. Here, engineers need to accurately determine the loads that will act on the structure. This includes analyzing all possible combinations of these loads to ensure safety. The structural analysis is more precise than in earlier stages, eliminating any earlier approximations. The final products are then documented in detailed drawings and specifications that outline member sizes, details, quality of workmanship, the applicable building codes, a bill of materials, and the overall project cost.

Consider this stage as the final dress rehearsal before a play. The script is complete, but now the directors and actors perfect their lines and cues, ensuring everything works flawlessly before the actual performance begins. They have a detailed list of props, costumes, and what everyone needs to do, just like the drawings and specifications in engineering.

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