Proceedings of 41st Danubia-Adria Symposium Advances in Experimental Mechanics (pp. 79-82)
АУТОР(И) / AUTHOR(S): Anđela Perović 
, Miloš Matejić , Vladimir Milovanović
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DOI: 10.46793/41DAS2025.079P
УВОД / INTRODUCTION:
Headless screws are commonly used fasteners in mechanical engineering, especially in applications where the screw must be flush with the surface it secures.
In real working conditions, this type of screw is often exposed to axial forces, which may result from tightening or from external loads. Therefore, it is important to understand how axial force affects a headless screw connection in order to ensure a reliable and strong joint. Monitoring the axial force, which may be either tensile or compressive, is a key factor in maintaining joint safety and preventing plastic deformation.
Recent studies have explored various nondestructive methods for determining axial force in screws. One such method is the ultrasonic technique based on the acoustoelastic effect, where the screw is divided into specific zones and the measurement error is typically below 10%. By introducing corrections to the clamping length and using suitable sensors, this error can be reduced to below 3%. In addition, advanced ultrasonic technologies allow for more accurate measurements by eliminating errors caused by poor sensor contact with the material. On the other hand, experimental methods are used as a complement, as they are performed under actual load conditions and take into account factors such as friction and microslip.
The aim of this paper is to experimentally determine the axial force occurring in headless screws used to connect the outer and inner parts of a mechanical joint. The behavior of the screws under compressive load will be analyzed, and the results will contribute to a better understanding of the mechanical performance of headless screw connections.
Future research will focus on modifying screw parameters in order to examine whether the length and diameter of the screw affect its strength and behavior under load. In addition, the influence of repeated (cyclic) loading on headless screws will also be considered.
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ПРОЈЕКАТ / ACKNOWLEDGEMENT:
ЛИТЕРАТУРА / REFERENCES:
- Zhao, X.-X., Li, Y.-M., Liu, X.-G., Yao, K. Ultrasonic measurement on axial force of highstrength bolt in service. Journal of Low Frequency Noise, Vibration and Active Control, 2020, 39(3), 596–603. doi: 10.1177/1461348418815405.
- Liu, J., et al. Experimental and numerical studies of bolted joints subjected to axial excitation. Wear, 2016, 346–347, 66–77. doi: 10.1016/j.wear.2015.10.012.
- Pan, Q., Pan, R., Shao, C., Chang, M., Xu, X. Research Review of Principles and Methods for Ultrasonic Measurement of Axial Stress in Bolts. Chinese Journal of Mechanical Engineering, 2020, 33(1). doi: 10.1186/s10033-020-0431-x.
- Jing, X., Dai, H., Xu, W., Zhao, Y., Zhang, J., Yang, B. Axial Load Measurement of Bolts with Different Clamping Lengths Based on High-Frequency Ultrasonic ZnO Film Sensor. Sensors, 2023, 23(7), 3712. doi: 10.3390/s23073712.
- Hitachi Ltd, Kitazawa, S., Hitachi Ltd, Lee, Y., Patel, R. Noncontact measurement of bolt axial force during tightening processes using scattered laser ultrasonic waves. ReJNDT, 2023, 1(1). doi: 10.58286/28211.
- Deutsches Institut for Norming. DIN 913 – Hexagon Socket Set Screws with Plat Po. Deutsches Institut for Norming (DIN), 1980. https://www.aspenfasteners.com/content/pdf/Metric _DIN_913_spec.pdf. Accessed June 22, 2025.