Time -dependent distributed load on cantilever beam.

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Hi there,

I'm trying to re-modeling a time-dependent load cantilever beam as shown in fig.1. The result obtained from Scaled Boundary Finite Element is shown as fig.2.

I did defined the interpolation function as shown in fig.3 and 4. It looks identical with the original function. Then, I assigned Output times for time dependent study as shown in fig. 5. I've got the displacement vs. time as shown in fig. 6 but it didn't even closed to fig.2 at all.

My noticed, during time = 0.02-0.03, time variation is equal to -1, meaning load is acting downward so the displacement should be negative values. My displacement are all in positive values which I thought it wasn't make sense at all.

Please help and I really appreciate it.

Best regards, KM.



2 Replies Last Post 2024年7月16日 GMT+2 12:49
Henrik Sönnerlind COMSOL Employee

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Posted: 1 month ago 2024年7月15日 GMT+2 12:34

In fig. 6, you are plotting the magnitude of the displacement, which is a quantity that by defintion is positive. It is the vector norm if the displacement. If you want signed results, you need to look at an individual displacement component.

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Henrik Sönnerlind
COMSOL
In fig. 6, you are plotting the magnitude of the displacement, which is a quantity that by defintion is positive. It is the vector norm if the displacement. If you want signed results, you need to look at an individual displacement component.

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Posted: 1 month ago 2024年7月16日 GMT+2 12:49
Updated: 1 month ago 2024年7月16日 GMT+2 15:41

Dear Henrik,

Thank you for your advise. Here is fig.7 after changing total disp to y-displacement. Even both shapes are not identical yet, but it has a good trend same as fig.2. The only thing that bothered me is a linear line instead of smoothed line as in fig.2.

1.How can I plot a smoothed curve?

Best regards, KM.

Dear Henrik, Thank you for your advise. Here is fig.7 after changing total disp to y-displacement. Even both shapes are not identical yet, but it has a good trend same as fig.2. The only thing that bothered me is a linear line instead of smoothed line as in fig.2. 1.How can I plot a smoothed curve? Best regards, KM.

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