Calculation of seismic qualities of the damper and vibration transducer with the possibility of their use in aircraft

The aim of the work. The article aims to determine the most effective seismic protection devices, as well as their degree of reliability in different conditions. The method of comparative calculation for determining the quality of seismic protection devices is given. An example of calculation for the damper and vibration transducer is carried out. Calculations show that the use of seismic protection devices reduces the coefficient of K 3 more than twice. Seismic protection is an urgent problem not only in construction, but also in all branches of the technosphere. The option of using seismic protection devices in aircraft is also considered. Methods. A comparative calculation of the behavior of dampers and vibration transducer taking into account the friction coefficients f tr, the sum of vertical loads ∑ Qkd , the total shear seismic force ∑ Sdc is considered. The diagram of the location of seismic protection devices (damper and vibration transducer) under the building is presented, as well as the options for installation in aircraft are given. Comparative calculations are carried out with the presence of seismic protection installations and without them. Results. The total result is given taking into account the change in the value of horizontal seismic loads Sik , which has changed in the range of 2.26-2.46 times. This circumstance allows to conclude that the proposed damping device reduces the seismic load, which falls on the protected structure, by 1-2 points, with almost the same efficiency as the vibration transducers (difference of 0.3 times).

Innovative design and analysis of a longitudinal-torsional transducer with the shared node plane applied for ultrasonic assisted milling

This paper presents an innovative design and development of a longitudinal-torsional ultrasonic vibration transducer. This longitudinal-torsional ultrasonic vibration transducer can be stimulated up by one group of longitudinal piezoelectric ceramics and it has a shared longitudinal and torsional vibration node plane. The longitudinal-torsional ultrasonic vibration transducer consists of two amplitude horns, a mounting flange, and four pieces of axially poled piezoelectric ceramics. Theoretical analysis and formulation of the share vibration node have been studied, which are used to guide the design of the transducer. Five helical grooves are cut off along the circumference of the amplitude horn so as to convert the longitudinal vibration to both longitudinal and torsional vibration at the same time. Simulations have confirmed that each longitudinal-torsional vibration mode has one shared node on the transducer. The vibration amplitude is measured by a laser displacement sensor and the largest longitudinal displacement of longitudinal-torsional ultrasonic vibration transducer reaches 6 µm and torsional displacement reaches 11 mrad when 500Vpp voltage is applied on the transducer. Ultrasonic vibration milling experiments have shown that the longitudinal-torsional ultrasonic vibration transducer has played a great role in the cutting process as the longitudinal-torsional ultrasonic vibration milling decreases the cutting force substantially compared to the convention milling operations.