Dynamic characteristics of a hydraulic curved pipe subjected to random vibration

In this paper, based on the finite element method, the K type common jacket structure connection in the form of positive connection and reverse connection conditions is being do comparative analysis. Research focus on dynamic characteristics, including of power spectrum analysis under the action of random vibration and fatigue properties of two kinds of connection type structure. The calculation results show: the inverted K type connection of jacket structure is about 10% increase in the stiffness and the dynamic performance, the inverted K type connection form is more worthy of popularization and application in engineering.

Download Full-text

Dynamic Characteristics of Structures With Bolted Joint

Analysis of Bolted Joints ◽

10.1115/pvp2002-1085 ◽

2002 ◽

Author(s):

Shigeru Aoki

Keyword(s):

Natural Frequency ◽

Dynamic Characteristics ◽

Random Vibration ◽

Damping Ratio ◽

Pressure Vessels ◽

Bolted Joints ◽

Simplified Model ◽

Piping System ◽

Bolted Joint ◽

Acceleration Response

Bolted joints are widely used for pressure vessels and piping system. Many studies on strength of bolted joint are carried out. However, few studies on dynamic characteristics of structure with bolted joint are carried out. In this paper, the effect of bolted joints on dynamic characteristics of structure is examined. First, the damping ratio and the natural frequency of specimens with some types of bolted joints are measured. Obtained results are compared with those for the specimen without bolted joint. It is found that damping ratio increases and the natural frequency becomes lower. Next, the effect of bolted joint on random vibration response of structure using simplified model is examined. Standard deviation of acceleration response of structure with bolted joint is lower than that of structure without bolted joint.

Download Full-text

CubeSat’s Deployable Solar Panel with Viscoelastic Multilayered Stiffener for Launch Vibration Attenuation

International Journal of Aerospace Engineering ◽

10.1155/2020/8820619 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Shankar Bhattarai ◽

Hongrae Kim ◽

Hyun-Ung Oh

Keyword(s):

Solar Cells ◽

Free Vibration ◽

Dynamic Characteristics ◽

Random Vibration ◽

Solar Panel ◽

Structural Safety ◽

Vibration Attenuation ◽

Vibration Tests

Ensuring the structural safety of a deployable solar panel under a severe launch vibration environment is one of the important factors for a successful CubeSat mission. A CubeSat’s deployable solar panel proposed in this study is effective to guarantee the structural safety of solar cells by attenuating launch loads owing to the superior damping characteristic achieved by a multilayered stiffener with viscoelastic acrylic tapes. The demonstration model of 3 U CubeSat’s deployable solar panel was fabricated and tested to validate the effectiveness of the proposed design. The basic dynamic characteristics of the solar panel were measured through free-vibration tests according to the various layers of the stiffener. Moreover, the characteristics of the deployed solar panel were measured and investigated under various temperatures to predict its capability under in-orbit operation. The effectiveness of the proposed design for launch vibration attenuation was demonstrated through qualification level sine and random vibration tests.

Download Full-text