The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The modal experiment analysis of large structure is effective method of structure health evaluation in new century. Nowadays, the modal experiment data of transmitter tower is few, and moreover the modal experiment of whole transmission tower is nearly blank. This paper study and provide the modal experiment method of whole transmission tower which be stationary reference point and mobile measure...
Arch is a typical complex structure comparing with beam and plate in bridge system. This paper investigates the damage characteristic combining the crack location with the crack intensity in arch. Initially, the first four displacement modes of intact and different damaged arch are simulated and the displacement mode changes are obtained. Next, the wavelet transformation is applied to the displacement...
The modal analysis and experimental study of Micro-expansive CFST coupled column single pylon cable stayed bridge was analyzed and its oscillating frequency and the corresponding mode were obtained from the calculation. A correlative analysis of the oscillating frequencies and modes both from the calculation and the experiments was carried out. The results from the correlative analysis proved that...
The honeycomb sandwich plate is applied widely in the modern spacecraft design because of its excellent capability. When the dynamic analysis of the spacecraft structure made up of the honeycomb sandwich plates is performed in ANSYS, the equivalent parameters of the honeycomb sandwich plates have to be identified. Now there have been three equivalent methods, that is called the sandwich theory, the...
We propose the use of a haptic touchscreen to convey graphical and mathematical concepts through aural and/or vibratory tactile feedback. We hypothesize that an important application of such a display will be in teaching visually impaired students concepts that are traditionally learned almost entirely visually. This paper describes initial feasibility studies using a commercially available haptic...
This paper presents, for the first-time, actuation and direction control of multiple gear-coupled surface micromachined ultrasonic motors. Using three Whispering Gallery Mode Micro Ultrasonic Motors (WGMMUMs) with different flexural resonances, the center motor motion is controlled to rotate clockwise (CW) and counter-clockwise (CCW) direction at controlled rotation speeds. The bulk-PZT actuates the...
A dynamic model of a flexible slewing beam in contact with the external environment is developed in this paper. The model is represented in the non-dimensional form. A definition of the percussion center of the flexible beam is introduced and its basic properties are established. It is shown that, contrary to the percussion center of rigid beam, for the flexible beam there exists infinite number of...
Electric motors is the backbone of many industrial process, however it consumes of large portion of energy. Increasing energy costs create incentives for movement toward higher efficiency systems. Large high speed induction motors which are operating on variable frequency drives with flexible rotordynamic designs are often required to have an accurate prediction of its modal characteristics (natural...
In this study, we propose the concept of dynamics-based visual inspection for the verification of structural dynamic properties of a vibrating object; the inspection method involves the analysis of the vibration distribution of the object by using a high-frame-rate video. Under unknown ambient excitation, modal parameters of an excited object are simultaneously estimated to determine its input-invariant...
A novel approach to fault feature extraction using Weibull distribution parameters is proposed. After the original signal of bearing vibration is modeled as the Weibull distribution, its scale parameter is extracted as a new feature vector for the bearing running state. The tests results of fault diagnosis of the rolling bearing verify that this new feature can catch the regularity of changes in the...
A method based on finite element model is presented that is used to identify stiffness of mechanical joint. By means of shock excitation, response of the system is obtained in which joints are included. Fourier Transform is used to obtained response spectrum of system. Based on FEM, the system model including joints is build and then low order natural frequencies are obtained by modal analysis. Natural...
The slideway design is the key in designing the disc vibrating feeder, however, a reliable and theoretical guidance has not come into existence, which greatly restricted the appliance of CAD(Computer-aided design). Based on the similarity principle and exist code system, a new coding method applicable to slideway design is brought forward. More detailed information about the parts could be supplied...
The sensitivity of the damage index is important to the identification of structural damage. Through the dynamic test of three unbonded pre-stressed concrete beams, the methods of shape parameter damage identification and curvature modal damage identification were taken to assess the damage degree and the damage location of experimental beams. The information fusion technology based on D-S evidence...
With large scale increases of the train speed, it is of great practical significance to develop a fatigue test stand for high-speed train's transmission system. 3-DOF (three degree-of-freedom) electro-hydraulic shaking table for high-speed train's transmission system fatigue test is designed and its three dimensional mathematical model is established in this paper. In addition, static analysis and...
The research on shape coefficient is the central issue of the wind study and the criterion constitution. In this paper, an 800kV ultra high voltage transmission line was studied. The ambient excitation testing and the time-domain method were used to study the shape coefficient of the transmission tower. The wind speed on the top of the tower was measured by the anemometer DT-80, while the acceleration...
Based on the new COSCO Building, First, the wind pressure distribution of four typical wind angers were especially studied in CFD analysis. Second, WAWS method (weighted amplitude wave superposition) was used to simulate the fluctuating wind velocity time-history, which fits Davenport power spectrum and spatial correlation. Finally, the wind vibration coefficient is obtained by applying the Gust Load...
According to the mechanism of the relative change rate of mode shape(RD), a new damage identification quantity called the Vibration Mode Slope Change Rate(RD') is put forward. The new quantity is analyzed with the fundamental principles of function differential method. By means of SAP2000, Finite element analysis on the damage detection for two-span RC. frame beams is carried out, which are preset...
In recent years, research on using wireless sensor networks (WSNs) for structural health monitoring (SHM) has attracted increasing attention. Unlike other monitoring applications, detection of possible structure damage requires significant amount of domain knowledge that computer science researchers are usually unfamiliar with. As a result, most previous work in WSN-based SHM was done by researchers...
This paper presents the design and testing of an image contour display system with vibrotactile array. The tactile image display system is attached on the user's back. It produces non-visual image and permits subjects to determine the position, size, shape of visible objects through vibration stimulus. The system comprises three parts: 1) a USB camera; 2) 48 (6×8) vibrating motors; 3) ARM micro-controlled...
Analytical method and software technology of finite element plays a very important role in mechanical structural analysis. Suspension failure is one of important factors affecting the Rice Rope Direct Seeding Machine in life. In this paper, three kinds of structure of virtual model of the suspension equipment is set up with the assistance of UGNX three-dimensional software, on SOLID element type as...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.