Journal of Acoustics and Vibration Research

Identification of the Modal Parameters of a Golf Club

Mon, 30 Jun 2025 00:00:00 +0000

The dynamic behaviour of a golf is a critical role in its performance, user comfort, and structural durability during both the swing and impact phases. An Accurate understanding of its vibration characteristics, particularly the natural frequencies, mode shapes, and damping, is essential for optimizing its design and enhancing the user experience. However, most numerical models of golf clubs rely solely on finite element predictions with limited experimental validation, leading to significant discrepancies in mode shape and frequency correlation. The absence of experimentally validated data limits the reliability of such models in real-world performance evaluation. This study aims to identify the modal parameters of a golf club through both numerical and experimental approaches. A finite element model of a golf club is developed from a measured CAD model. The FE model created using an optimal element size of 2 mm is calibrated to match the Experimental Modal Analysis (EMA) results of the test club. EMA is performed on the golf club using an impact hammer and roving accelerometers under free boundary constraints. The comparison between the FE and EMA results shows substantial discrepancies, indicating the inability of the FE model to accurately reproduce the dynamic behaviour of the golf club. The results clearly demonstrate that accurate material properties and experimental validation are essential for reliable dynamic modelling. This study establishes a foundation for improving golf club design through integrated numerical–experimental approaches.

Monitoring Valve and Spark Plug Failures using Z-Freq Statistical Analysis

M. I. M Isa, N.A Ngatiman, M.I.M Ahmad, S.M. Saad, M.Z. Nuawi — Mon, 30 Jun 2025 00:00:00 +0000

Engine problems such as spark plug misfire, valve clearance and valve cracks are the failures that lead to engine malfunction if engine continues in operation and require early detection. Machine learning can be used to automatically diagnose engine problems, but a high success rate is still a barrier because a significant amount of training data is needed. Therefore, in order to examine the specific frequency characteristics, this new fault analysis approach will take into frequency content throughout the Fast Fourier Transform (FTT) procedure. Z-freq, a dynamic vibration signal analysis for non-deterministic data that focuses on frequency domain rather than time data, is a new statistical signal-based analysis that can easily be used to improve these vibration-induced faults studies at this stage for further enhanced investigation. This examination examines the time and frequency domain of data acquired from Proton, Toyota, and BMW engines operating at various speeds between 750 and 3000 rpm. In order to replicate the real effect, the fracture fault was made using a wire cut method for 0.25, 0.5, and 1.0 mm, while the clearance fault was set using a screw and sheet gauge for clearance thicknesses of 0.0, 0.2, 0.3 mm during experimental tasks. The voltage applied to a particular spark plug will be cut to simulate a misfire issue. High sensitivity, space-saving, and long-lasting piezo-based sensors are used to assess vibration caused by spark plug misfire, valve clearance and valve crack. Piezo-film, micro-fiber composite, and accelerometer sensors are employed in this experiment. To guarantee precise and accurate observation, all of these sensors were calibrated using the Bruel and Kjaer type 4294 calibration exciter. The main finding is that the distribution of Z-freq data for normal, misfire, valve clearance, and valve crack shows a notable pattern in the coefficient value.

Sound Intensity Mapping of Power Generators in Solar Energy Systems: A Case Study on Inverter Noise Emissions

J.M. Zikri, M.S.M Sani, M.F.A. Izran, J. Muriban, G.S. Prayogo — Mon, 30 Jun 2025 00:00:00 +0000

This study examines the acoustic emissions produced by power generators in solar energy systems, with a particular focus on inverters. Noise emissions from these systems are frequently overlooked, despite their potential environmental and health effects. Sound intensity mapping (SIM) was conducted at two distances (0.3 m and 1.0 m) and at three different times of the day to identify noise hotspots and characterize variations in sound power levels (SWL). The inverter, a crucial component of solar systems, was found to generate substantial noise, with SWLs reaching as high as 89 dB during peak operation. The findings underscore the significance of acoustic analysis in the design of solar systems and propose mitigation strategies to reduce noise exposure in sensitive environments. This research advocates for the incorporation of acoustic considerations into the planning and implementation of sustainable energy systems.

Investigation of the Modal Parameters of a Cricket Bat via Simulation and Experimental Modal Analysis

Mon, 30 Jun 2025 00:00:00 +0000

The dynamic behaviour of a cricket bat significantly influences its overall performance, particularly in relation to ball rebound, power, control, and player comfort. Despite its importance, the relationship between bat structure and dynamic response remains insufficiently understood. This study aims to investigate the modal parameters of a cricket bat, with the goal of enhancing performance and reducing the risk of injury due to repeated impact during gameplay. To achieve this, an integrated approach involving Finite Element analysis (FEA) and Experimental Modal Analysis (EMA) are used to determine modal parameters such as natural frequencies, mode shapes and damping ratios, The FE model of the cricket bat is developed based on the actual dimensions of the physical cricket bat test. Normal modes analysis is then performed using MSC Nastran to compute the natural frequencies and mode shapes of the bat. These results are compared with the EMA results to evaluate the accuracy of the simulated results. The study shows notable differences in modal frequencies, with error ranging from 0.73% to 26.70%. These discrepancies highlight the complexity of reproducing bat dynamics accurately through FE models. The findings of the study indicate that the dynamic behaviour is highly sensitive to material properties, particularly Young’s Modulus and density. This study provides valuable findings on the complex dynamic behaviour of cricket bats. The results can assist players in selecting bats that align with their playing style and support manufacturers in optimising bat performance, enhancing player safety, and improving overall player experience.

Dynamic Response of Simple Plate Structure Under Various Boundary and Excitation Condition

N.A.Z Avdullah, M.S.M Sani — Mon, 30 Jun 2025 00:00:00 +0000

The dynamic response of plate structures is a fundamental concern in engineering due to its critical role in ensuring the safety, reliability, and performance of various systems. Plates are commonly subjected to a wide range of boundary conditions—such as clamped, simply supported, and free edges—and may experience different types of excitations, including harmonic, impulsive, and stochastic loads. This study presents an analytical and numerical framework to evaluate the vibration characteristics of plates under multiple boundary constraints. The primary objective is to characterize the modal behavior of plates as influenced by different boundary conditions. Using finite element analysis, the natural frequencies and mode shapes of the plate are investigated to assess the sensitivity of its dynamic response to support conditions. The findings provide detailed insights into how boundary restraints affect structural vibration behavior, which is essential for mitigating resonance risks, minimizing fatigue damage, and supporting the design of resilient structural components. This work contributes to the field of structural dynamics by offering a predictive basis for the dynamic analysis of plate-like structures in aerospace, civil, and mechanical engineering applications.