Session: FSI-01-01 Thermal Hydraulic Phenomena with Vessels, Piping and Components

Paper Number: 65813

Start Time: Tuesday, July 13, 2021, 09:00 AM

65813 - Flexural Vibrations of a Multi-Material Microhydraulic Hose Subjected to External Excitation. Experimental Research and Theoretical Description 

The development of technology forces designers to look for ways to reduce the weight and dimensions of hydraulic elements while maintaining their operating parameters. Often, completely new materials are used for this purpose. The use of composite materials in the design of microhydraulic elements can be seen more and more often. The paper presents experimental research and mathematical modelling of flexural vibrations of a composite hydraulic microhose. The tested object was a Polyflex 2020N-013V30 hydraulic microhose, consisting of a braided aramid layer placed in a thermoplastic matrix. The vibrations were induced with an external electromagnetic exciter in the range from 0 Hz to 200 Hz using the sweep function. Using a laser vibrometer, the element vibration velocity was measured in the first three modes. Long exposure photos were also taken to identify the form of these vibrations. The influence of the mean pressure in the system and the flow rate on the frequency and amplitude of natural vibrations was assessed. The experimental tests showed that the natural frequency of flexural vibrations of the element increased with the increase of the mean pressure in the system. With the increase of the flow rate, however, the frequency of the vibrations dropped. The existence of considerable non-linearity in subsequent natural frequencies was also shown. At the same time, mathematical simulations were carried out using the Mathematica software. For the analytical description of the object's vibrations, partial differential equations based on the string equation were used. A part responsible for damping in the material was added to the classical equation of the string. Further development of the proposed model will allow for modelling the internal pressure in the hose and its effect on transverse vibrations. It will also allow to design of vibrations of composite microhoses and avoid the coupling of these vibrations with external excitations.

Presenting Author: Marek Lubecki Wrocław University of Science and Technology

Authors:

Marek Lubecki Wrocław University of Science and Technology
Michał Stosiak Wrocław University of Science and Technology
Mirosław Bocian Wrocław University of Science and Technology
Kamil Urbanowicz West Pomeranian University of Technology in Szczecin