Applied Mechanics and Materials Vol. 611

Abstract: In this contribution a comparison of the results of deformation analysis performed in a classical way using strain gage and modern way, when a non-contact digital image correlation method was used, is described. Both methods were applied simultaneously for the investigation of the aluminum sample with stress concentrators loaded by tension, what prevented the investigation by different conditions. The contribution includes also the comparison of the results obtained using digital image correlation method by different levels of smoothing filters, which the software delivered together with correlation system contents.

Abstract: The contribution describes an original optical measuring technique serving for the investigation of temperature influence on the shift of investigated objects natural frequencies. The mentioned method uses a modified high-speed digital image correlation system with original program Modan 3D created in Matlab, by which it is possible to non-contactly determine the natural frequencies using complex mode indicator function (CMIF) or normal mode indicator function (NMIF), the mode shapes as well as the damping ratio. Influence of the temperature on the shift of natural frequencies was analyzed at the planar steel specimen of circular shape with three holes. To the excitation a modal hammer was used. The specimen heating was realized by a hot-air gun, whereby the influence of the elevated temperature on the shift of natural frequencies was investigated by three temperatures distinguishing the room temperature 50° C, 75° C and 100° C.

Abstract: Paper deals with dust mass concentration measurement in working environment. The measurement is focused to respirable dust fraction, which is dangerous for people. Light scattering principle of dust mass concentration measurement is used for this purpose. Also cyclone as mechanical way of separation of respirable fraction can be used for this purpose. Next problem is determination of uncertainty of this measurement.

Abstract: This article deals with automated welding conceived as a robotic welding cell. Laser scanners used in automated welding are described in the main part of the article. Then, the control scheme of the robotic welding is defined. Several simple algorithms are proposed for the data processing. Emphasis in these algorithms has been placed on simplicity, so that they can run online. Algorithms have been verified on several scenarios.

Abstract: Sensor systems are an essential part of automated equipment. They are even more important in machines that come in contact with people, because they have a significant impact on safety. This paper describes the design of active feedback for rehabilitation device driven by pneumatic artificial muscles. Here are presented three methods for measuring the load of the robot. The first is a system composed of Force Sensitive Resistors (FSR) placed in the handle of the device. Two other methods are intended to measure the load of the actuator composed of artificial muscles. The principle of one method is to measure the difference in filling pressures of the muscles, second is based on strain measurement in the drive cables. The paper describes advantages and disadvantages of using each of these methods in a rehabilitation device.

Abstract: This contribution is focused on the analyze the possibilities of increasing the power of two-stroke internal combustion engine and their consequential execution in the practice. Currently dealing with these issues major manufacturers of motorcycle international brands, but also service technicians of professional riders, as well as regular users of motorcycles. The basic objective of this paper is the issue of increasing power output for single-trace motor vehicles, and objective of the experiment was to increase performance through volumetric efficiency, i.e. increase indicated mean effective pressure. The results of the experiment were tested on the specific equipments and in practice. In conclusion paper presents the benefits and results of the experiment. By means of measurements on the performance brake, in the final stage of paper is tested by how much increased power output of the engine after modification, compared to the production engine.

Abstract: The paper deals with experimental simulation measuring and the analysis of defect distribution in passenger car tire under dynamic loading. The main reason for detection of defect extension is to recognize an influence of closed air, small bubbles, separations in tire and it is mainly connected with its quality during its service in a vehicle in terms of road safety. This analysis should help constructors to solve critical conditions in tire casing, whether material selection and individual components proportions are suitable and fit or even the whole construction of tire casing is suitable. The reason for detection of internal defects in tire casing is to avoid the wear of those tires which already contain some internal defects and already recognised separations, which could propagate during the movement of vehicles. This is closely connected with the occurrence of tire destruction and the main purpose is to prevent its critical status and later vehicle crash and human life menace.

Abstract: The paper deals with the analysis of uncertainty of tilt measurement using accelerometer. Low cost accelerometer based on the principle of heat array is used for tilt measurement. One chip microcontroller is used for data processing from accelerometer. The knowledge of uncertainty of measurement for this measuring chain is necessary for our application.