Closure to “Discussions of ‘Transverse Vibration of a Viscoelastic Column With Initial Curvature Under Periodic Axial Load’” (1970, ASME J. Appl. Mech., 37, pp. 556–557)

1970 ◽  
Vol 37 (2) ◽  
pp. 557-557
Author(s):  
K. K. Stevens
Keyword(s):  
Transverse Vibration ◽  
Axial Load ◽  
Initial Curvature ◽  
Viscoelastic Column

Transverse Vibration of a Viscoelastic Column With Initial Curvature Under Periodic Axial Load

1969 ◽  
Vol 36 (4) ◽  
pp. 814-818 ◽  
Author(s):  
K. K. Stevens
Keyword(s):  
Polymethyl Methacrylate ◽  
Transverse Vibration ◽  
Axial Load ◽  
Dynamic Instability ◽  
Complex Modulus ◽  
Lateral Vibrations ◽  
Lateral Response ◽  
Viscoelastic Column ◽  
Linear Viscoelastic ◽  
Frequency Curves

The lateral response of a slightly curved viscoelastic column subjected to a periodic axial load P0 + P1 cos ωt is investigated. The analysis makes use of the complex modulus representation for linear viscoelastic materials. It is shown that the lateral vibrations stemming from imperfections can be of significant amplitude. Experimentally determined amplitude-frequency curves for a polymethyl methacrylate (Plexiglas) column are presented, and are found to be in excellent agreement with the theory. It is shown that there is an analogy between the dynamic instability and the static buckling of imperfect columns.

scholarly journals Effect of temperature on non-linear dynamical property of stuffer box crimping and bubble electrospinning

2014 ◽  
Vol 18 (3) ◽  
pp. 1049-1053 ◽  
Author(s):  
Jian-Xin Huang ◽  
Min-Feng Song ◽  
Hai-Yan Kong ◽  
Ping Wang ◽  
Ji-Huan He
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Thermal Effect ◽  
Transverse Vibration ◽  
Mass Production ◽  
Axial Load ◽  
Dynamical Property ◽  
Effect Of Temperature ◽  
Production Ratio ◽  
Axially Moving

The velocity of axially moving slender fiber of viscoelastic fluid is an important factor in mass-production of crimped fibers in stuffer box crimping and bubble electrospinning. A governing equation for fiber crimp is obtained by the Hamilton?s principle, and the natural frequency and critical axially moving velocity are obtained analytically by considering the thermal effect. It is concluded that a high temperature gradient can greatly enhance the production ratio and guarantee the fundamental transverse vibration. Additionally the effects of the tensile axial load and amplitude on transverse vibration are also elucidated.

scholarly journals Spatial Transverse Vibration Simulation Model of Axially Moving Sucker Rod String under the Excitation of Curved Borehole

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Hongbo Wang ◽  
Shimin Dong
Keyword(s):  
Transverse Vibration ◽  
Axial Load ◽  
Simulation Models ◽  
Elastic Collision ◽  
Axial Motion ◽  
Runge Kutta Method ◽  
Sucker Rod ◽  
Simulation Results ◽  
Axially Moving ◽  
Vibration Simulation

The mechanical model of transverse vibration of sucker rod string (SRS) in directional well is simplified to the transverse vibration model of longitudinal and transverse curved beam with initial bending under borehole constraints. In this paper, besides considering the excitation of alternating axial load on the transverse vibration of SRS, it is proposed for the first time that curved borehole is also the main excitation for the transverse vibration when the SRS moves reciprocating axially in the borehole. Based on the elastic body vibration theory, the transverse vibration mathematical model of SRS with initial bending under borehole constraints is established. In this model, the curved borehole excitation caused by the axial motion and the alternating axial load excitation is considered. Besides, the elastic collision theory is applied to describe the constraint of tube on the SRS transverse vibration in this model. Then the fourth-order Runge–Kutta method is used to calculate the transverse vibration of SRS in directional wells. The simulation results show the following: (1) The simulation results of the three simulation models in this paper are different. The results indicate that the curved borehole excitation caused by the axial motion and the alternating axial load excitation is the main excitation for the SRS transverse vibration. (2) In directional wells, the rod and tube contact along the well depth, and the dangerous sections locate at the deviation section of the borehole and the compression section of the rod. On the whole, the contact force between rod and tube in deviation section of borehole is larger. The transverse vibration of the compression section of the rod is the most violent.

Effects of bottom plate in friction stir welding of AA6061-T6

2020 ◽  
Vol 118 (1) ◽  
pp. 108
Author(s):  
M.A. Vinayagamoorthi ◽  
M. Prince ◽  
S. Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Axial Load ◽  
Weld Zone ◽  
Welding Process ◽  
Bottom Plate ◽  
Welding Parameters ◽  
Nugget Zone ◽  
Friction Stir ◽  
Weld Joints ◽  
Fine Grain

The effects of 40 mm width bottom plates on the microstructural modifications and the mechanical properties of a 6 mm thick FSW AA6061-T6 joint have been investigated. The bottom plates are placed partially at the weld zone to absorb and dissipate heat during the welding process. An axial load of 5 to 7 kN, a rotational speed of 500 rpm, and a welding speed of 50 mm/min are employed as welding parameters. The size of the nugget zone (NZ) and heat-affected zone (HAZ) in the weld joints obtained from AISI 1040 steel bottom plate is more significant than that of weld joints obtained using copper bottom plate due to lower thermal conductivity of steel. Also, the weld joints obtained using copper bottom plate have fine grain microstructure due to the dynamic recrystallization. The friction stir welded joints obtained with copper bottom plate have exhibited higher ductility of 8.9% and higher tensile strength of 172 MPa as compared to the joints obtained using a steel bottom plate.

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