Mechanical concept design- Types of Design problems

The various types of design problems which design engineers solve in work . A breakdown of what they entail.

The primary responsibility of design engineers is to solve design problems. Design problems come in varying shapes and sizes depending on the specialization, product or industry . There are many underlying similarities across various problems solved and can be categorized into three domains.

  1. Conceptualization
  2. Analysis and improvement
  3. Manufacturability and Producibility

Conceptualization:

The first step in creation of a new design. Coming up with ideas and creating concepts of components/ assemblies/systems.

Creating new types of features, original designs. New mechanisms, new structures.

  1. Identifying and understanding the customer's needs and requirements.
  2. Translating user requirements into technical specifications.
  3. Generating novel and innovative design concepts that meet the defined requirements.
  4. Balancing the trade-offs between different design options.
  5. Defining the desired functionality and performance of the product.
  6. Ensuring that the design meets or exceeds performance expectations.
  7. Choosing appropriate materials based on their mechanical properties, cost, and availability.
  8. Considering factors like strength, durability, and weight.
  9. Designing components that seamlessly integrate into the overall system.
  10. Ensuring compatibility and proper functioning of interconnected parts.
  11. Addressing safety concerns and ensuring the reliability of the design
  12. Identifying potential failure points and implementing preventive measures
  13. Considering budgetary constraints and designing cost-effective solutions.
  14. Balancing performance requirements with cost considerations.
  15. Designing with manufacturing in mind

Analysis and Improvement:

Analysis and improvement design problems in mechanical design typically occur in the later stages of the design process, after the initial concept has been established. These problems involve detailed analysis, optimization, and refinement of the design to ensure it meets performance criteria, standards, and user expectations.

If we are already having an existing design and we need to improve the performance of the design Iin various aspects.

  1. Function
  2. Strength and structural integrity
  3. Durability
  4. Safety
  5. Ergonomics
  6. Sustainability
  7. Cost

Any problem-solving activity in evaluating an existing design or configuration based on parameters as mentioned above and consequent improvements in design associated with those analyses or evaluation.

Conceptualization and analysis with improvement are iterative in nature.

Here is an example of a Tow hook design and a static stress analysis done on it giving the below result.

Common types of analyses include:

  1. Structural Analysis:
  2. Thermal Analysis:
  3. Fluid Dynamics and Aerodynamics:
  4. Vibration Analysis:
  5. Failure Mode and Effects Analysis (FMEA):
  6. Optimization of Performance:
  7. Reliability and Durability Improvement:
  8. Cost Reduction and Value Engineering

Manufacturability and Producibility:

This activity is generally carried out in the Detail design phase when the concept is finalized and functional performance has been optimized. Then the manufacturing aspects are optimized to reduce the cost and time required to get the final product .

Whether its converting the base geometry of a part to something which can be forged adding allowances, drafts, fillets and chamfers or it may be reducing the number of parts and integrating multiple parts into one. Reducing the time to assemble and reducing effort of assembly are all considerations during the design process for manufacturability.

The design engineer has to keep in mind the practicalities associated with the process .Design around specific constraints with minimal compromise on performance.

  1. Design for manufacturing and Assembly
  2. Tolerance stacks
  3. Setting GD&T drawing tolerancing scheme

A GD&T drawing :

Generic Problem statements generally put forth towards the design engineer :

1. Apply a known mechanism to a new application
2. Apply a new material to an existing part
3. Design to make stiffer
4. Design to make stronger
5. Make the design more friendly for manufacture
6. Make the design into a modular assembly
7. Reduce the number of parts of an assembly
8. Reduce weight
9. Reduce cost
10. Make more compact
11. Reduce overhangs
12. Make a design more sustainable for the environment
13. Add fool proofing mechanism
14. Add Safety mechanism
15. Add additional functions
16 . Simplify the assembly

Categories: Skills and knowledge

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