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# What do we do to fill the Physics Gaps

### Simulation gives you everything.

• Idealise do geometric and material modeling.
• Simulate and interpret results.
• Play around with material options
• Play around with support conditions.
• Know your design space and optimize geometry.

### REMEMBER KISA: KEEP IT SIMPLE ALWAYS

Derivable pleasure decreases as the entropy (tidiness of the room increases) against derivable mechanical energy run downhill as the entropy of the system increases.

### Converting fresher to a designer

 Step 1 Make the facts native Step 2 Use algebraic physics to explain equations Step 3 Build clarity on problem definition Step 4 Build feel for numbers Step 5 Advanced design facts Step 6 Kindle the imagination on specific product situation to achieve the solution

### Example 1

Sophistication: Young’s modulus reduces with temperature hence stiffness reduces (axial, bending, shear, torsional) as for isotropic materials.

Native expression: When you heat the metal, it is easy to stretch, bend and twist hence temperature reduces stiffness or increases flexibility.

### Example 2

Sophistication: Stiffer system has higher natural frequency

Native expression: Stiffer component hurries back to original position so takes less time to oscillate to and fro.

### Example 3

Sophistication: Bearing support structure reduces the stiffness of shaft system if the bearing support structure is not rigid.

Native expression: If you support the shaft on hard supports, shaft deflects less but if supported on flexible supports it deflects more.

### Example 4

Sophistication: Gyroscopic effect provides damping unlike physical does not dissipate energy.

Native expression: If no air resistance and no friction in the bearing a fan spins perpetually. Hence any work supplied to overcome the inertia does not dissipate rather is stored as kinetic energy in the fan.

Note: Gyroscopic effect leads to whirling disc consuming of extra energy, thus stiffening the component.

Also, do build facts for inertia.

### Pedagogical step 3: Build clarity on problem definition

• Why I need a vibration margin?
• If I do modal analysis, I get a large number of frequencies. Which should I be interested in?
• What is the gap between the first fundamental frequency and the worst operating speed?
• Should I consider speed and frequency coincidence only when it sustains for a significant period (dwelling resonance and not passing resonance)?
• Why do not we compute axial frequencies generally?
• Why margin is generally established against flexural natural frequency and why not torsional?

### Pedagogical step 4: Build feel for numbers.

• What material typically shaft is made from and what are the mechanical properties?
• Is the mass of the shaft significant compared to elements supported by it?
• How much young’s modulus reduces with temperature?
• What are the temperatures for various product lines?
• Typical shapes of bearing support structures and stiffness numbers
• List goes on!

### Pedagogical step 5: Advanced design facts

• Now introduce Campbell diagram.
• Explain how to construct and how to read?
• Spend explaining all possible excitation agencies use powerful animations and native narration keeping it almost non-technical.
• The excitation lines will then have the following order numbers: motor 1X, 2X, variable frequency drive 6X, 12X, 18X, etc., for a motor with two poles with a variable frequency six pulse VSI (voltage source inverters) drive.
• Torsional frequency not influenced by speed only flexural frequencies.
• List goes on!

### Give a typical sketch of shaft bearing support structure system and start asking questions.

• What happens if we redesign the shaft?
• Could we vary cross sectional thickness does manufacture support it?
• What happens if we redesign bearing support structure?
• Could we replace the material? How it impacts design and benefits

### Team INNOVENT

Preparing thinkers for tomorrow!

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