Load cell placement in load pin 2

[jayakumaran]

I want to know how these strain gauges are kept inside the load pin?, look image for reference.
I know using adhesive glue these guages are fitted but my question is inside? or outside(surface of the load pin grooves)?
if inside, how these are kept?. if outside, how these can be sealed?, please someone give me a solution,
or any other better place to fit these gauges please suggest me,Thanks in advance.

 

[TugboatEng]

The gauges are on the inside bore of the pin. My understanding is that it's not usually the gauges that fail but the signal amplifier instead. Consider mounting the amplifier remotely from the pin so that it can be replaced without removal of the pin.

 

[jayakumaran]

thanks for your time and consideration, i apologize if i made any confusion, i just want to know where is the best place to fit these strain guages in the load pin, that is where is the maximum stress and strain happened ?, please give me solution sir.

 

[TugboatEng]

The strain gauges are installed inside of the bore of the pin. Some pins have grooves on the OD to concentrate stresses, some don't have grooves. The reality is that you can install the gauges anywhere and build a calibration curve with test loads. You'll probably want to chose geometries that maximize linearity and minimize hysteresis.

 

[jayakumaran]

The strain gauges are installed inside of the bore of the pin. Some pins have grooves on the OD to concentrate stresses, some don't have grooves. The reality is that you can install the gauges anywhere and build a calibration curve with test loads. You'll probably want to chose geometries that maximize linearity and minimize hysteresis.

"I apologize for the delay, and thank you, sir. I have another question: If I install gauges inside the bore of the pin using adhesive, they tend to detach due to the rotational nature of the CALM buoy platform. Is there an alternative installation method to ensure the gauges remain securely attached for at least 10 years?"

 

[TugboatEng]

I would look closely at your adhesion process. Bonding to corrosion resistant materials requires some additional considerations. For example, I would media blast the bore of your pin immediately before installing the gauge. Also consider using adhesion promotors.

 

[jayakumaran]

ok sir, thank you so much.

 

[dtimberlake]

Haven't had my first coffee yet, but what popped into my head is that I wouldn't put strain gages on the neutral axis.

 

[jayakumaran]

Haven't had my first coffee yet, but what popped into my head is that I wouldn't put strain gages on the neutral axis.

"Yes, those grooves experience the highest strain and stress. That’s why I placed the gauges inside the pin, aligned with the groove area for better measurements."

 

[jayakumaran]

"Now I have one more question, sir. Since the strain gauges are fitted inside the bore of the pin using adhesive, how are they placed? Are they inserted through the hole using a needle or similar tool? If so, wouldn’t it be impossible to position the gauges inside the groove area, as it’s 200mm away from the pin’s center hole? Please take a look at the attached image for reference."