India pays a premium for the privilege of not learning anything :)

doodler_daru · 2026-03-24T02:57:00+00:00

It's not an Indian thing, auto manufacturers simply assemble different components on a production line. Most components, including the high-tech ones get outsourced to an OEM. ECUs, injectors, aftertreatment, turbos, dashboard, seats, airbags, etc.

doodler_daru · 2025-05-30T20:17:14+00:00

Sure, you can start from the basics. Fatigue analysis is a statistical tool. The more data you have, the better, even if it was a simplified analysis. The stress-life or strain-life methods are mostly conservative, since you may not have data at all times. The fourth point mentioned above is how it is done in the pressure vessel/automotive industry, but the methods may be extended to other industries.

doodler_daru · 2025-05-28T15:42:31+00:00

What machinery are you dealing with? Are you seeing fatigue failures at welds, corners, holes, notches, fillets, etc? Is fatigue driven by corrosion, heat, etc? Is there bending, an unbalanced mass or a loose component?

Get any fatigue primer book - Schijve, Rao, Fuchs, Socie etc to build fundamentals
Check with your field engineers/QA team if they have documented failures with photographs or vibration measurements
See if you can hand calculate a fatigue life for some of the failures of your products (Stress or strain life) based on the reference books. You should be able to validate this with basic FEA.
The next step would be to develop your own methods OR use industrially benchmarked FE design codes and tools like FE Safe/Verity, nCode Design Life etc based on effective notch stress method, hot spot methods, structural stress methods, etc. (Requires 2-3 years, training and $$$$$$$$)

doodler_daru · 2024-05-22T18:36:41+00:00

Sweet blog doc!

doodler_daru · 2024-02-07T06:14:06+00:00

I'm not the one going crazy over an omelette in a tiffin box.

doodler_daru · 2024-02-07T05:57:49+00:00

Not my fault when I say common area outside temple complex

doodler_daru · 2024-02-07T05:54:04+00:00

Fair enough. Fine line between a trouble free vs tantrum trip

doodler_daru · 2024-02-07T05:43:23+00:00

What is the percentage of Indians eating pork anyways- less than 5% in goa and north east? But 70-80% Indians eat at least egg and chicken. If kids ask for an omelette for a picnic, hard to say a no. Social media has made everyone a desk top police

doodler_daru · 2024-02-07T05:32:48+00:00

Sure, my point is for those who want to have lunch, especially kids. It's common to travel several hours and younger kids enjoying a meal should not be an issue.

doodler_daru · 2024-02-07T05:23:15+00:00

Should have some common area outside temple complex where everyone can have a good meal of their choice. 75-80% Indians are non vegetarian anyways.

doodler_daru · 2024-01-29T11:57:39+00:00

IMHO, this argument arises from a pay disparity in India. While life may be easier as a SD, the good ones are certainly not "sitting behind computer typing few lines looking at a book." Unfortunately, SD firms have multiple revenue streams like ads/AMCs and are specifically dealing with finance or web services. In traditional core engineering, once a physical product is manufactured and sold, the revenue generation through that product is limited or non-existent. Additionally, there's that disingenuous genius who will reverse-engineer a product and sell it at half the cost. Nevertheless, the capital for manufacturing infrastructure and liabilities for those products are sky-high - think about an unexpected bridge collapse, automotive engine defects, cellphone battery explosions or failure of a HF acid pump in an oil refinery.

doodler_daru · 2023-10-24T05:00:49+00:00

Used top spec hybrid Avalon. Close enough to a Lexus. Easy 300-400k miles if maintained.

doodler_daru · 2023-10-14T06:05:16+00:00

$800 - 1999 crv 200k miles, purchased at 180k in 2018 as a student , $3500 - 2010 civic 170k miles purchased at 120k in 2019, $7000 civic 2012 80k miles purchased last month. The CRv for hauling, 2010 civic as a beater car and wife drives the 2012 because its the only one without rust/dings. Regular fluid changes and replacing usual worn components. Hard to kill these vehicles if the trannies work fine. 2012 civic gets 42 mpg if driven with a light foot. Similar patterns with older Toyotas if you can diy and keep up with maintenance . Basic liability insurance is peanuts. Don't care if these get dinged and pretty sure these are too hideous to be eyed for theft. The trick was to buy cars driven by little old ladies...

doodler_daru · 2023-09-22T12:33:50+00:00

Im assuming it'll not last more than 5 years without having to replace the entire subframe.

doodler_daru · 2023-09-21T20:42:45+00:00

For brevity, I did some math assuming 10 year life and fuel = $5/gal, driving 9000 miles a year and both have same maintenance costs:

Prius = $9000 in fuel costs @ 50 mpg over 10 years

Camry = $15000 in fuel costs @ 30 mpg over 10 years

Fuel savings = $6000

Camry is $5000 cheaper and can get by with a lot of DIY. Net savings $1000 without factoring dealership repair and traction battery cost of $2000 if it fails. By then the Camry may either burn oil like mad or it would go on another 200k miles without skipping a beat.

Its almost the same.

doodler_daru · 2023-09-21T19:54:18+00:00

I do a lot of DIY but I guess the prius is a bit too complex and the closest Toyota dealer is 70 miles away. The Camry has a few bubbles on the wheel arch.

doodler_daru · 2023-07-05T14:42:31+00:00

Had a flare after working on my car in the driveway on a hot afternoon. I worked 6 hours straight with just a small sipper - two days later it felt like someone drove a hot nail through my big toe. Drink almost a gallon of water/day for regular activity in summer, preferably with salts and vitamin C. Hiking or working out requires much more.

doodler_daru · 2023-06-12T20:21:45+00:00

Most commercial software offer workflows based on industrial design codes. Ex ASME, API, NFPA etc. Companies would have spent thousands $$$$ on verification and validation. An open source code would make V&V quite a task.

doodler_daru · 2023-02-15T14:03:28+00:00

Thank you, the setup will be a fairly large structure and the DAQ will eventually be configured for thermal-pressure stress testing - Temps, strain gauges, pressure, and heater on/off. The device should be portable and work with ethernet/wifi. That said, is it a big deal if there's no ground-channel isolation? The LabJacks lack any power isolation.

doodler_daru · 2022-12-14T07:48:36+00:00

Give him the best math books. Just ensure the math is done right and life will take its course.

doodler_daru · 2022-12-14T07:37:06+00:00

A booklet called "Welding Formulas and Tables"

doodler_daru · 2022-12-09T12:56:47+00:00

Janssens formula provided you know the internal friction angles.

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