The Ingenious Design of Strain Gauges
Вставка
- Опубліковано 19 лют 2024
- Watch my bonus video on load cells: nebula.tv/videos/the-efficien...
Get Nebula using my link for 40% off an annual subscription: go.nebula.tv/the-efficient-eng...
---
This video explores the fascinating world of strain gauges, these clever little devices that combine elements of mechanical engineering, electrical engineering, and materials science to give us a way of measuring the deformation on the surface of an object.
3D Model Credits:
Hand model modified from "Hand" by Soady - cgcookie.com/projects/realist...
---
If you would like to support the channel, please consider becoming a Patron - / efficientengineer .
This will allow me to create more high quality videos covering a range of engineering topics.
---
The Efficient Engineer is a channel aimed at mechanical and civil engineers. The mission is to simplify engineering concepts, one video at a time!
Follow me on Twitter: / efficiengineer
What are some other interesting strain gauge applications?
If you're interesting in the companion video on load cells you can check it out on Nebula at this link: nebula.tv/videos/the-efficient-engineer-how-do-load-cells-work
Hey how about ARTIFICIAL GRAVITY 🎉 😁
I'm a regular ol sky-walker😂🎉 yay for me
ua-cam.com/users/shortsaw2Zjrv6zkw?si=DA2IPe0O_CNWZn1p
Got some video ideas from my mechanical engineering career :
Metal Additive Manufacturing
Ceramics
Super alloys
Circuit boards :o
Coatings & Machining tooling
If this guy produces 3000 hours of content this channel will effectively replace need for mechanical engineering colleges
Well you'd still need to do practice problems to prove you understand the concepts, but I agree with your sentiment lol
@@nickbell3546 ofcourse practice is most important I am just speaking in hyperbole to convey a point
@@removenameI don’t think you’ve been to engineering school if you think some UA-cam videos are a sufficient replacement. At least not in the US
@@mattmurphy7030I don't know what's more hilarious, the fact that you didn't understand they are being hyperbolic, or the fact that you think US engineering schools are good.
@@mattmurphy7030There is no reason that educational videos cannot replace engineering universities. I went to Caltech. My siblings went to MIT. All back when both of these schools were meritocracies instead of the woke garbage factories they are becoming now.
As a former calibration tech in the Marines and for Lockheed, I used to calibrate strain gauges and the calibration equipment used calibrate them. Fast forward a few years and I became a Turbofan Test Engineer for Lockheed and Rolls-Royce and used to mount the strain gauges on the N1 fan (big fan in the front of high bypass jets) for R&D testing.
I'll never forget those experiences!
Very cool job. Great work!
which skill sets are required to get this type of job.
The Author said that the strain gages were used in the resistance mode. After looking at the construction, can these gages be used in the capacitive mode too using an oscillator instead of a Wheatstone Bridge?
Can an outsider get a job like this in the US ?
This is gold! You're one of the few UA-camrs who has not once compromised on quality. Your videos have taught me a lot and have ignited my passion for studying and working in engineering.
This is probably the best concise explanation I can send to people about what I do. However, there is one thing that is wrong. Passive temperature compensation is what is described as "active" by using a second gage in the half bridge. ACTIVE is measuring and compensation through thermal calibration, EG you actively have to do something such as math such as read a temperature sensor (RTD, thermistor, etc) then calculate the new impact. When it's just one, we tend to say it's uncompensated and NOT passive. There are all extreme temperature cases where you'd select a different STC code than for the underlying material as you might be in a different area of the curve and can get better performance in high temp or cyro applications.
Really? I always thought that relying on the STC of the gauge was sufficient for isothermal tests and was passive. I too have used the word active for describing the half bridge technique.
I've certainly never used your method of active compensation, however I've never used a gauge outside of -40C to +200C so the need has never really been there...
Never met a strain gauge.
@@aaronacj Severely underrated comment
Fun fact, wheatstone bridge is also used for temperature measuring, but thermistor Is placed instead of gauge.
Thermistor or rtd
This time I have to leave a comment. Today I was discussing with a colleague how principle strains from my simulation can be compared to our future experiments. And then you upload this video… Thank you 🙏🏼 😊
There seem to be two people that invented the strain gauge at essentially the same time, Arthur Ruge and Edward Simmons. Simmons had a lengthy legal fight with Caltech over the patent rights. Simmons became a fairly notable eccentric later in life and was a fixture around the Caltech campus.
Renaissance Ralph
That’s the problem with developing things at universities, they get to share the credit.
Fantastic quality as always, i love that you never compromise on quality and uploads your videos when they are done and up to your high standards!
You do a really great job of presenting new information and then pacing things to let the viewer guess ahead at the next step, and it makes your videos really enjoyable.
For example, I loved the way you showed the multiple gauge bridge configurations first, raising the question “why would you do that?”, then moved on to talking about thermal expansion, and gave me just enough time to excitedly shout “oh you could put one on an unstrained reference material!” at the screen.
Would be cool if you could cover different ndt methods used for different material. A bit more on the niche side of mechanical engineering but equally important
brilliant video thanks for all your work, your ability to unpack complex subjects is unparalleled
thank you guys for putting the effort out to produce such quality content, this is my second year in ME and I see a long future for me in this channel. Keep up the good work
Great video as always!
Merci!
excellent content, very informative and very simply explained
absolutely wonderful video! I hope to see more!
Great video. I'll be using this as a source for training. Thank you!
You keep impressing me everytime. good job mate and thank you
Excellent description of strain gages and the Whetstone bridge.
I was desperately waiting for the new video.
I am wondering what softwares can be used to create these fantastic animations? Congrats for an amazing video!
He said he uses Blender
Yup!
@@TheEfficientEngineer How long does it take to make the video (excluding the time spent on planning and refining what you wish to present)?
@@aaabbb-py5xda rule of thumb for general post production you can figure about an hour of work for every minute of finished video. So 20 minute video -> 20 hours editing. I’m not an animator, so I don’t know how much that adds or overlaps with the edit process.
@@rjhornsby Thanks for the input. It seems like a full time commitment, which I shouldn't mind since I can spend 20 hours straight playing games xD
Amazing and highly informative video. Thanks for publishing such good content😊
I don't know how to thank you for creating and sharing this content. Was very useful.
very good job! thank you very much!
I have used a similar mechanism in one of my projects, very useful
Outstanding content. I am a retired petroleum engineer, but my daughter is a civil engineer/project manager for a pipeline design and build company. I will be giving her a subscription to Nebula.
Very informative 👍👍👍👍
Congrats on 1M subs! As a mechanical engineering student you're helping me so much :)
Thank you so much for making videos like this. I am going to share this with my boss, who has a PhD in Material Science, so he can understand how I am going to use a strain gauge to compensate for thermal expansion in my experiments...
I love your content. Some remarks: at 0:24, there seems to be intense curvature beyond the supports which I think is wrong. At 13:52 I think that the shear strains (green half-arrows) have the wrong directions.
damn, well done! Looks an awful lot like a device I'm currently making a video about, but luckily it's completely different
I use strain sensors as a hobbyist to experiment with measuring impact force, energy, deceleration. With my oscilloscope, I can measure the strain over time, which gives me the duration of the collision, and thus the decelerative G-load on the projectile, for example. And I don't even need an Arduino!
Arduino can’t even start to keep up with your osmelloscope
Be careful with high speed strain measurements. The gauge itself has a frequency bandwidth which if not allowed for can give low readings.
Rule of thumb is smaller gauge length is faster, but I'm not an expert in dynamic measurements so other factors probably come into play.
Awesome as always
A perfect video.
love your content
Very nice video
Love your work
I love this channel
hearing the words Mohr’s Circle gave me flashbacks to AE lab like i was back in Nam 😂
Great to see that
highest grade of content right here gents and ladies
Congratulations for 1M🎉
Keep up the good work! This is a perfect channel for civil students to visualize their study materials. If you ever want to collab, let me know!
Here is a fun fact to know and tell. If you take a strain gauge, and wire it to a capacitor bank, and then, after charging the capacitor bank, you dump this current onto the strain gauge, the strain gauge behaves like an exploding bridge wire detonator (EBWD).
Can you make one on method of characteristics? That'd be great!
Good 👍
Can you please attach some study materials in all of your videos?
Already your videos are top notch. Including that factor will complement the video and guide the viewer for a comprehensive learning.
I use to see one of the inventors of the strain gauge, Edward Simmons, rummaging in the electronics part stores (when they still existed) in Pasadena, CA, from the 1970s thru 1990s. He was a bit eccentric, but all the other old timers that engage with him, did it with much respect. He made a fortune, but not from the strain gauge, but investments in oil companies.
Renaissance Ralph, as he was called, always wore opaque tights, some kind of short toga outfit, sandals and a hat, and was often seen on campus at Caltech. He was rumored to sometimes wash his hair in the fountains, but I never actually saw that happen.
Can you please create a video on : industrial hydraulics and pneumatics
Wonderful video! Thanks!
Please upload frequently I am waiting for your videos 🥲🥲
📝 Summary of Key Points:
📌 Strain gauges are crucial tools in engineering for measuring how objects deform under loading, aiding in structural integrity monitoring and performance optimization.
🧐 The electrical resistance strain gauge is a common design that measures strain by detecting changes in electrical resistance as the object deforms, with materials like Constantan being popular due to stability over temperature.
🚀 Wheatstone bridge circuits are used to accurately measure small changes in resistance of strain gauges, enabling precise strain calculations and monitoring.
💡 Additional Insights and Observations:
💬 "Understanding the basic concept of strain is crucial for appreciating how these devices work."
📊 Gauge factors and material properties play a significant role in determining the sensitivity and accuracy of strain gauges.
🌐 Temperature compensation methods like active and self-compensation are essential to mitigate errors due to thermal expansion.
📣 Concluding Remarks:
Strain gauges are versatile devices that play a vital role in engineering applications, offering precise measurements of strain and enabling detailed analysis of structural behavior. Understanding their principles and applications is key to ensuring the reliability and efficiency of various mechanical systems.
Generated using TalkBud
did someone say FULL BRIDGE REC----- oh sorry wrong full bridge
Great explanation as always, please remember to create content and upload 😅
Is there any recommended manufacturer for purchasing strain gauges? Many thanks!
Wasn't this channel called real engineering or something?
Banks use strain gauges in the building process of vaults
How they bond it to the metal?
So, how do they measure the strain that the strain gauge measures?
Just i want to study, thanks!
0:00 I did that in a lab today!!!
Excellent! But what is a micro strain(in this context it is a unit of measure??)??
1 strain is stretching something to be 100% longer. Ie If I have a 1m length of material and I pull it until it's 2m long, it has a strain of 1.
If I pull it until it's 1.001m, it has 1 millistrain. If I pull it until it's 1.000001m long, it has 1 microstrain. So 1 microstrain isn't very much!
Fun fact for you if you're interested in such things: strain is a dimensionless quantity. An area is length squared. A volume is length cubed. Strain is length ÷ length, and therefore has no dimension.
Thanky you❤
Strain gauges and strain rossets are they same ?
Strain rosette is a particular arrangement of strain gauges that provides multiple dimensional measure at once
One video for unite conversation
SI unit change
@ 4:38 the red lead for the multimeter is in the wrong place 😆
Whoops!
Does a strain gauge have a built in memory for analysis later?
No
@@90_98 Too Bad.
ATIVA A FAIXA DE AUDIO. POR FAVOR
Excellent!
great vid!
For concrete . can we use guges like this ? lvdt are better for concrete , am i right ?
Bond the gauge to concrete using epoxy and it will work
LVDTs measure deflection not strain.
Rule of thumb for strain measurement of concrete is gauge length >=3× the size of your aggregate.
hmm so as an EE i highly doubt that wheatstone bridges are used for anything strain gauge when you can have a constant current source and a differential amplifier to measure the voltage across it and divide by the fixed current source for the resistance measurement
You'd be wrong. Wheatstone bridges are used all the time in this application.
Assuming 15mA excitation, 350 gauge and 2.0 gauge factor, the difference between readings for a 1uStrain measurement is about 10.5uV on a 5.25V reading. Not impossible, but unwieldy and uncompensatable.
Wheatstone bridges are used because it's a lot cheaper, and you can use compensation techniques. The downside is that you need high precision/very stable resistors in your circuit. Think $20 to $50 per resistor
I should also mention that by using the WS bridge, you're measuring a voltage relative to 0, therefore amplification is easy.
The wheatstone bridge offers a number of advantages for wiring strain gages in various configurations to cancel out unwanted effects on the strain gage. The full bridge configuration in particular is very useful. For example, a full bridge using the "chevron" rosette shown at 16:16 can be wired up to cancel strains caused by off-axis and bending loads and only respond to strains induced by torque.
Constant current can also be used in strain gage measurements, but there are disadvantages there too.
@@lancehadfieldwhat are those disadvantages? I can make nano amp accurate temperature compensated current sources, theyre easy.
I assume those devices take into account change of material due to change in temperature.
You have to factor that in by your own curves using thermocouples
Techniques are mentioned in the video.
I should have paid you the tuition fee of my engineering college
Bruh the multimeter lead is in current socket not ohms lmao
0:27 cable stayed bridge with piers on the main span --> not efficient! God damn I came here looking for efficiency and this is what I get...
So you came to the wrong place, you problem
Is the narrator the gaming historian?
Didn't cover the full bridge.
This video was uploaded too late 😢
..👍
nothing new for people already involved in weighing. Wheatstone bridge circuit is employed No electrical. Just pure electronics required. Easy said in theory, in practical a lot of factors must be considered. 😅😅
I'm constantly amazed at the subtleties involved in the governing equations. As you say, simple in theory, but complicated in its nuances.
TOO LONG TO CREATE NEW VIDEOX
2021-Civ-325
Guys your videos are amazing but please… the music is so annoying it’s like you’re in a romantic date
Can’t even hear the music. You problem