Mohammad Tahaye Abadi; Mehdi AlizadehYazdi; Mohammad Ali Farsi; Mohammad Ebrahimi
Volume 7, Issue 4 , January 2015, , Pages 51-62
Abstract
The paper concerns with the experimental analysis of the pyroshock wave propagation in the structure of Kavoshgar's payloadon the ground. The source of waves is the explosion of pyrotechnic materialacting as the actuator of separation mechanism for the payload subsystems. The shock sensors are attached ...
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The paper concerns with the experimental analysis of the pyroshock wave propagation in the structure of Kavoshgar's payloadon the ground. The source of waves is the explosion of pyrotechnic materialacting as the actuator of separation mechanism for the payload subsystems. The shock sensors are attached in different locations of structure to measure the acceleration amplitude along three orthogonal directions after the activation of pyrotechnic material.The experimental setup is used for measurement of the acceleration history as well as the evaluation of the shock response spectrum at specific locations during two-stage separation of payload subsystems. The experimental acceleration record is evaluated to eliminate the noise signals and incorrect data. The variations of shock  response at different payload locations are evaluated to determine the amplitude attenuation of the wave passing through the structure body and joints. The measured data are also employed to determine the working condition and design criteria for the equipment of Kavoshgar payload.
M. Tahaye Abadi; H. Kashani; N. Ariaeifar
Volume 2, Issue 1 , April 2009, , Pages 25-34
Abstract
The paper presents a kinematical model for a random positioning system which simulates microgravity conditions on the ground. The random positioning system contains two frames, with an experiment platform. The frames are rotated around two perpendicular axes by a random angular velocity that it causes ...
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The paper presents a kinematical model for a random positioning system which simulates microgravity conditions on the ground. The random positioning system contains two frames, with an experiment platform. The frames are rotated around two perpendicular axes by a random angular velocity that it causes continuous changes in the orientation of experimental sample relative to the gravity’s vector. The angular velocity between random values is changed based on specific function in order to limit the generated spurious acceleration below a preselected threshold. The kinematical model yields criteria to evaluate the microgravity conditions on ground base. Such criteria are defined based on the mean values of acceleration and gravity components which are sensed by the rotating experimental sample.
