Calculating Secondary Creep: Tin/Lead Solder Lab Report

In summary, calculating secondary creep involves understanding the relationship between strain and time for a given material at a constant temperature. The two commonly used equations are the Norton-Bailey equation (for materials with a logarithmic relationship) and the Power Law equation (for materials with a power law relationship). To calculate secondary creep for your tin/lead solder, you will need to analyze your extension vs. time graphs and determine which equation fits the data better. Then, you can use the equation to calculate the strain at different time intervals.
  • #1
DGal91
1
0
Hi all, new to the thread due to a lab report being in tomorrow!

Basically if anyone could shed some light on how to calculate secondary creep..
In uni we have undertaken a lab report on tin/lead solder and given two formulaes to calculate the ε.

ε = αlnt + c
ε = βt^m + c

Temperature constant at 23°C
mass of 2kg used

ive plotted the extension vs time graphs on excel but now stumped where to go due to never coming across this field in uni.

Any help is greatly appreciated and if any other information is needed feel free to ask.

Thanks all, Dan
 
Engineering news on Phys.org
  • #2


Hi Dan,

Calculating secondary creep involves understanding the relationship between strain (ε) and time (t) for a given material at a constant temperature. The two formulae you have been given are commonly used to calculate secondary creep for different materials.

The first formula, ε = αlnt + c, is known as the Norton-Bailey equation. It is used for materials that exhibit a logarithmic relationship between strain and time, which is often the case for metals. In this equation, α is a material-specific constant, lnt is the natural logarithm of time, and c is a constant that takes into account any initial strain or deformation of the material.

The second formula, ε = βt^m + c, is known as the Power Law equation. It is used for materials that exhibit a power law relationship between strain and time, which is often the case for polymers and other non-metallic materials. In this equation, β is a material-specific constant, t is time, and m is a material-specific exponent.

To calculate secondary creep for your tin/lead solder, you will need to determine which of these equations is more appropriate for your material. This can be done by analyzing your extension vs. time graphs and determining which equation fits the data better.

Once you have determined the appropriate equation, you can use it to calculate the strain at different time intervals. For example, if you have data points at 1 hour, 2 hours, and 3 hours, you can plug those values into the equation and solve for the corresponding strain values.

I hope this helps. If you have any further questions or need clarification, please feel free to ask. Good luck with your lab report!
 

1. What is secondary creep?

Secondary creep is a phenomenon that occurs in materials under constant stress or load. It is characterized by a gradual and continuous deformation or strain over time, even though the applied stress remains constant. This is different from primary creep, which is the initial rapid deformation that occurs when a material is first placed under stress.

2. Why is calculating secondary creep important?

Calculating secondary creep allows us to understand and predict the long-term behavior of materials under constant stress. This information is crucial in engineering and designing structures and components, as it helps ensure their safety and longevity.

3. How is secondary creep measured?

Secondary creep is typically measured by plotting the strain or deformation of a material over time under a constant stress. The slope of this graph represents the rate of secondary creep, which can be used to calculate the creep rate or strain rate.

4. What is the significance of the Tin/Lead Solder Lab Report for calculating secondary creep?

The Tin/Lead Solder Lab Report provides valuable data on the creep behavior of this specific material under different stress levels and temperatures. This data can then be used to better understand the factors that influence secondary creep and make more accurate predictions for other materials.

5. How can we reduce the effects of secondary creep?

There are several ways to reduce the effects of secondary creep, including using materials with higher strength and stiffness, designing structures with lower stress levels, and incorporating stress-relieving features such as fillets and chamfers. Additionally, proper maintenance and regular inspections can help identify and address any potential issues caused by secondary creep.

Hot Threads

Recent Insights

Back
Top