Tuesday, 16 July 2019

# Material Selection with Flowcharts,Phases in Design, Spring back, Design Thinking

Material Selection with Flowcharts, Phases in Design, Spring back, Design Thinking: Material selection plays a vital role in the field of design. In this article, I will be explaining how to do the Material Selection in Mechanical Design with the help of Flowcharts along with the design thinking process with 6 phases of design. Apart from that, I will explain about Spring back in design and Determination of Shear center in the sections.

Flowcharts include design tools, Market Requirements, Material data needs, etc. The detailed explanation about the flowcharts for material selection in Mechanical design is as follows.

Flowchart for Material Selection in Mechanical Design:

The flowchart for Material Selection includes 3 steps which are as follows.

1.Design Tools

2.Market Need

3.Material Data needs

These three combined together and produce Product Specification.

1.Design Tools:

• Function Modelling
• Viability studies
• Approximate Analysis
• Geometric Modelling
• Simulations method
• Cost Modelling
• Component Modelling
• Finite Element Modelling
• DFM and DFA.

2.Market Need:

• Concept
• Embodiment
• Detail

3.Material Data Needs:

• Data for all materials, low precision, and detail.
• Data for a subset of materials with higher precision and detail.
• Data for one material with highest precision and detail.

The connection between these 3 steps was shown in the above figure.

Now, I will be explaining about the Design Thinking process along with the 6 Phases in Design.

Design Thinking-6 Phases in Design:

1. Recognition of need
2. Definition of problem
3. Synthesis
4. Analysis & Optimization
5. Evaluation
6. Presentation.

Explanation of 6 Phases in Design:

1.Recognition of need:

The recognition of the need must be checked during designing or planning a program.

One of the examples for Recognition of need is the transportation system in which different aspects are to be considered and are as follows.

Ex: Transportation Equipment

• Faster transportation system
• The transportation system should be Economical i.e initial cost and running cost.
• There should be lesser environmental pollution due to transportation.

2.Definition of the Problem:

All the specifications are to be specified while defining a problem like What is the output for this problem etc.

3.Synthesis, Analysis, and Optimization:

• Firstly, Synthesis is to be done and later Analysis is to be made on the required component so as to analyze the deformations, stresses, strains, etc present in the component.
• If the stress in the structure(which we had defined in the problem)is above the yield point, then it is a case of failure and we have to optimize it so that there should be no failure.
• If the stress induced in the structure is less than the yield point of the material then it is safe. There is no need to further optimize.

Now lets enter into our 3rd concept i.e. Spring back in design.

What is Spring Back in Design?

At the end of every metalworking operation, when the pressure on the metal is released, then there exists an elastic recovery by the material and the total deformation will get reduced a little called as Spring back in design.

• Spring back depends on yield point strength of the metal.
• Compensation can be made on spring back.

Compensation:

To compensate the spring back, the cold deformation must always be carried beyond the desired limit by an amount equal to spring back.

Let’s enter into our last concept i.e. location of shear center in sections.

How to determine the location of the shear center in the sections?

The shear center is also known as torsional axis, is an imaginary point on a section, where a shear force can be applied without inducing any torsion. In general, the shear center is not the centroid. In this article, I am going to explain how to determine the location of the shear center in the sections in a detailed manner.

The determination for the location of the shear center is shown below in the form of an image.

The shear center is defined as the point on the beam section where the load is applied and no twisting moment is produced.

• At the shear center, resultant of the internal forces passes.
• For symmetrical sections, the shear center is the center of gravity for those sections.
• We can place the loads at the shear center where there is a sliding problem in those sections.