Structural Dynamic Modification (SDM)
Structural Dynamic Modification focuses on making changes or modifications to a structure based on the analysis of its dynamic behavior. It involves identifying and addressing potential issues, optimizing the structural response, and improving the dynamic characteristics of the structure through physical or numerical modifications.
Structural Dynamic Modification is recommended when there is structural dynamic weakness detected through modal testing. We utilize computational mechanics technique to modify and optimize the structural design before implementing any actual physical fabrications and modifications.
The Flow
SDM involves both experimental techniques and computational mechanics
Experimental Techniques
Include conducting Experimental Modal Analysis (EMA) and Operational Deflection Shapes (ODS) to first troubleshoot potential issues of the structure.
Click here to read more on how our team implement the experimental techniques:
Computational Mechanics
Involves correlating a finite element (FE) model with the dynamic properties of the actual structure, which are obtained through experimental techniques. The problem can be identified through the correlation process, and modifications can be made and simulated using the correlated FE model. Approved modifications will be fabricated and tested on the actual structure.
Case Study
Step 1
The Problem
Through experimental techniques, it was found that the pump was dynamically weak in the axial direction, and high vibration was observed at its 1x running frequency (49.5Hz). There were also several similar horizontal-vertical modes at the region of 30-43Hz, indicating the equipment requires further strengthening work near to the baseplate. Thus, SDM was recommended.
Click here to read more on the experimental techniques performed for this case study:
Step 2
Correlation of FE Model
Correlating the FE model with the actual model in terms of the structural dynamic properties, i.e., natural frequencies and mode shapes
This process is conducted before performing any design modification on the FE model. The dynamic behaviour of the FE model should be close to the actual structure.
Step 3
Design Modification
As high vibration is observed at the 1x running frequency (49.5Hz) for this case study, the goal of SDM is to shift the modes away from this frequency region.
The suggested modification (red line in graph) on the base plate shows a shift in the natural frequencies of more than 10% for the first two modes. Below shows the shifted mode shapes in comparison with the actual structure:
Past Projects
- Operating Deflection Shape Analysis, Modal Analysis and Structural Dynamic Modification of P-102A & B Canned Motor Pump Package, Petronas Chemical Isononanol (PC INA), Johor, 19 September 2022
- Structural Dynamic Modification of Canned Motor Pump 3610-P-501 and 3610-P-601, Petronas Chemical Isononanol (PC INA), 13 August 2022
- Structural Dynamic Modification of Z-4601 Vapor Recovery Package, KPOC – Platform KBB Sabah, 19 May 2022
- Operating Deflection Shape Analysis, Modal Analysis and Structural Dynamic Modification of P-2320A Hydro Recycle Pump Package, BASF Petronas Chemicals SDN BHD, Pahang, 19 May 2022
- Operating Deflection Shape Analysis, Modal Analysis and Structural Dynamic Modification of RU-9060 Chiiled Water Unit, BASF Petronas Chemicals SDN BHD, Pahang, 25 February 2022
- Structural Dynamic Modification of KG-2020 HP Gas Expander Induction Generator, PC MTBE SDN BHD – PDH PLANT, Pahang, 2 August 2021
- Structural Dynamic Modification of Dynamic Diesel UPS unit no. 3&4, X-FAB Sarawak, Kuching, Sarawak, 17 June 2021
- Structural Dynamic Modification of P302-B Propylene Recycle Pump, Petronas Refinery and Petrochemical Corp (PRPC) / TecnimontHQC, 8 October 2020
- Structural Dynamic Modification of P122-A 2nd Reactor Outer Cooler Pump, Petronas Refinery and Petrochemical Corp (PRPC) / TecnimontHQC, 14 September 2020
- Structural Dynamic Modification of P103A & B Circulation Pumps, Petronas Chemical Isononanol (PC INA), 10 September 2020
- Structural Dynamic Modification of P-202 Stage I Dimerization Emergency Pump, Petronas Chemical Isononanol (PC INA), 15 July 2020