Sigitas Kilikevičius

Dynamic analysis of vibratory insertion process

Purpose – The paper aims to investigate theoretically and experimentally the process of compliantly supported peg insertion into a bush for high‐speed assembly, when vibrations are provided to the bush in the axial direction, and to analyse the influence of the parameters of the dynamic system and excitation on the assembly process.Design/methodology/approach – The mathematical model of parts vibratory insertion process is formed and the simulation is performed using a numerical computing software environment. The model includes inertia, compliance, dry friction, insertion speed and vibratory excitation. The three‐dimensional simulation of peg‐in‐hole insertion is accomplished using motion analysis software to test the influence of vibratory excitation on assembly failures, such as jamming and wedging. The experimental setup for the robotic vibratory assembly and the investigation methodology were presented. The experimental analysis of the vibratory insertion process of cylindrical parts with clearance i...

Estimation of the Drag Coefficient of Mine Imitator in Longitudinal Air Flow Using Numerical Methods

Abstract One of the most important measures to reduce the cost of preparing mortar units is the use of mortar shooting trainers operating according to the ‘shell in shell’ principle that best meets the needs of military forces. When increasing the efficiency of using equipment for mortar shooting training and seeking to reduce their production costs, further research on external ballistics is strictly necessary in order to improve the structural parameters of mine imitators. With the help of finite element modelling techniques, this article investigates air flow over mortar mine imitators. In order to achieve the aim, a package of Mechanical Desktop Software was used for creating a dimensional model of mine imitator the model of which was imported into ANSYS CFX and a finite element numerical model was generated. Considering the literary sources of experimental studies, SST turbulence model generating the results closest to those of experimental research was selected. After modelling, air drag force influ...

Experimental Investigation on the Friction Stir Spot Welding Process of Non-Ferrous Metals

This article presents an experimental investigation of the friction stir spot welding process in thin-walled plates by using a special HSS tool. A review of the literature dealing with the analyzed problem was conducted and the experimental setup for FSSW experiments was described. The experiments were carried out on non-ferrous 5754 aluminum alloy, copper M2 and brass CuZn37. Variations of experimental axial force were obtained.

Analysis of Aerodynamic Characteristics of the Rocket-Target for the „Stinger” System

This paper presents an analysis of aerodynamic characteristics of the rockettarget for the final training of shooting at aerial targets by the „Stinger” system service staff. The governing equations of fluid dynamics are presented and the computational model of airflow around the rocket is developed. ANSYS CFX computational fluid dynamics software is used to compute airflow velocities, pressure, the drag force and the drag coefficient. A practical implementation of the research is presented. Taking into account the simulation results, the rocket-target was designed and manufactured.

Experimental Investigation of Vibratory Peg-in-Hole Insertion for Robotic Assembly

The paper aims to experimentally investigate the process of a compliantly supported peg insertion into a bush with clearance by a robot, when vibrations are provided to the bush in the axial direction. The experimental setup of robotic vibratory assembly and the investigation methodology are presented. The experiments were performed by inserting the peg which is attached to a remote center compliance device by a robot into the bush mounted on an electrodynamic shaker. Durations of insertion process stages were measured under various combinations of excitation parameters of the bush. The experiments show that parameters of vibratory excitation have an influence on the duration of insertion process. By selecting suitable excitation parameters it is possible to shorten the insertion process duration and avoid jamming of the parts to be assembled.