Sökning: "High frequency vibration"

Visar resultat 1 - 5 av 82 avhandlingar innehållade orden High frequency vibration.

1. 1. Attenuation of hand-held machine vibrations. Application of non-linear tuned vibration absorber

   Författare :Hans Lindell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Impact machine; Hand-arm vibration; High frequency vibration; ATVA; Nonlinear tuned vibration absorber; White finger; HAVS; Transient vibration; Auto Tuned Vibration Absorber; Vibration dynamics; ISO 5349;

   Sammanfattning : Vibration injury in the hand-arm system from vibrating hand-held machines is one of the most common occupational health injuries and causes severe and often chronic nerve and vascular injuries to the operator. The objective with this study is to contribute to reduce hand-arm vibration injuries, first by developing methods of redesigning machines that will lower their vibration level and second to study how high frequency vibrations (HFV) above 1250 Hz effect the finger tissue which are not included in the current standard for risk evaluation. LÄS MER

3. 2. Truck Tyre Vibration Behaviour. Measurements and High Frequency Modelling

   Författare :Penka Dinkova; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration response; mobility measurements; truck tyre; heavy vehicle; tyre-road noise; tyre; driving point mobility; transfer mobility; tire; vibration prediction; model;

   Sammanfattning : To facilitate tyre-road noise prediction, a computationally efficient high frequency tyre model is needed. Such models are always a compromise between the desired accuracy and the need for simplicity. In addition the accuracy of models is often limited by the quality of the input data available. LÄS MER

4. 3. Vibration exposure of the glabrous skin of the human hand

   Författare :Ronnie Lundström; Ludwik Liszka; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Vibration; hand; skin; mechanical impedance; mechanoreceptors; tactile perception; high-frequency;

   Sammanfattning : An occupational exposure to hand-arm vibration can cause a complex of neurological, vascular and musculo-skeletal disturbances, known as the 'vibration syndrome'. However, the underlying pathophysiological mechanisms are not at all clear. LÄS MER

5. 4. Vibration-based Assessment of Tensegrity Structures

   Författare :Nasseradeen Ashwear; Eriksson Anders; Thomas Abrahamsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tensegrity; Pre-stress; Vibration; Health monitoring; Buckling; Temperature effect; Vibration health monitoring VHM; Optimization; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : Vibration structural health monitoring (VHM) uses the vibration properties to evaluate many civil structures during the design steps, building steps and service life.The whole function, expressed by stiffness and frequencies of tensegrity structures are primarily related to the level of pre-stress. LÄS MER

7. 5. Countermeasures against railway ground and track vibrations

   Författare :Robert Hildebrand; KTH; []
   Nyckelord :ground vibration; vibration screen; track vibration; railway vibration; seismic barrier;

   Sammanfattning : Railway track and ground vibrations are considered, with anemphasis on methods of mitigation ("countermeasures"), forapplication to wayside disturbance problems.Original field measurements from two sites in Sweden, aswell as borrowed measurements from Norway, provide vibrationresults at many points on the track, on and underneath theground surface, for a variety of trains, both with and withoutcountermeasures in-place. LÄS MER