ANALISIS KESALAHAN MAGNITUD FRF SISTEM GETARAN DUA DERAJAT KEBEBASAN
Investigation related with the influence of time record to the value of FRF’s magnitude has been conducted by previous researchers. This phenomena commonly found in FRF measurement on light structure using impulse excitation method with small disintegration constant. Unfortunately, previous resea...
Saved in:
| Main Author: | |
|---|---|
| Format: | Theses |
| Language: | Indonesia |
| Subjects: | |
| Online Access: | https://digilib.itb.ac.id/gdl/view/38246 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Investigation related with the influence of time record to the value of FRF’s magnitude has
been conducted by previous researchers. This phenomena commonly found in FRF
measurement on light structure using impulse excitation method with small disintegration
constant. Unfortunately, previous researchs had not yet mathematically reveal the
relationship between time record and error on FRF’s magnitude obtained from
measurement using impulse excitation method on two degrees of freedom system. In fact,
this relationship is very important in order to find out parameters that significantly
influence the FRF measurement using impulse excitation method. The parameter will give
good approach of the actual condition encountered in field.
In this research, analysis of impulse response spectrum error in two degrees of freedom
using proportional damping and general damping is done. The output of this analysis are
mathematical equations which accurately calculate the percentage of magnitude error of
the impulse response spectrum. To validate the mathematical equations, numerical
approach is also conducted. Validation is done by comparing the mathematical calculation
result with the simulation result from MATLAB. The next step is to observe the influence
of each parameter toward the impulse response spectrum error.
Based on the equation derived, observation result of each parameter is presented.
Therefore, optimum combination of parameters is obtained. The optimum combination is
then used to minimize the FRF’s magnitude error. From the combination of parameters can
be concluded that the number of frequency line and the value of the highest natural
frequency divided by the frequency span, give the same influence to the FRF’s magnitude
error. This is valid for either proportional or general damping case. In other words,
treatment given to reduce the FRF’s magnitude error during measurement will be the same
for both proportional and general damping case. |
|---|