scholarly journals Geometric Effect on the Nonlinear Force-Displacement Relationship of Awl-Shaped Serpentine Microsprings for In-Plane Deformation

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2864
Author(s):  
Meng-Ju Lin ◽  
Hui-Min Chou ◽  
Rongshun Chen
Keyword(s):  
Plane Deformation ◽  
Ductile Material ◽  
Obvious Effect ◽  
Taper Angle ◽  
Geometric Effect ◽  
Nonlinear Force ◽  
Displacement Force ◽  
Relationship Of ◽  
Force Displacement ◽  
Force Relationship

Even when made by brittle materials, awl-shaped serpentine microsprings (ASSMs) were found to have a nonlinear displacement–force relationship similar to springs made by ductile material. It is found that the nonlinear displacement–force relationship is due to the geometry and dimensions of the ASSMs. The geometric effect of the nonlinear force–displacement relationship of ASSMs for in-plane motion was investigated. A theoretical solution was derived to analyze this nonlinearity. By successfully fabricating and measuring an ASSM, the theoretical results agreed well with the experimental results. The results indicated that ASSMs have a nonlinear force–displacement relationship, which is similar to that of hardening springs. The taper angle has a significant effect on the nonlinear displacement of ASSMs. When the taper angle was small, no obvious effect appeared on the nonlinearity of the microsprings with different numbers of turns. When the beam length increased, the critical force for nonlinear deflection decreased.

Simulation Method of Soil Resistance on the Pushover Model of Group Pile Foundations

2012 ◽  
Vol 204-208 ◽  
pp. 981-985
Author(s):  
Yong Liang Zhang ◽  
Tian Bao Li
Keyword(s):  
Pile Foundation ◽  
Pushover Analysis ◽  
Simulation Method ◽  
Small Displacement ◽  
Advantages And Disadvantages ◽  
Elasto Plasticity ◽  
Nonlinear Force ◽  
Relationship Of ◽  
Force Displacement ◽  
Group Pile

Soil is a strong non-linear media and show obvious nonlinear under the small displacement of the foundation. Under the strong earthquake, the seismic performance of group pile foundation is closely related to the nonlinear force-displacement relationship of soil around the pile foundation and the elasto-plasticity o fpile. This paper introduces the nonlinear static pushover analysis of group pile foundation , summarizes the commonly used simulation method of soil around the pile foundation and compares the advantages and disadvantages of various simulation method.

Semi-inverse method for predicting stress–strain relationship from cone indentations

2003 ◽  
Vol 18 (9) ◽  
pp. 2068-2078 ◽  
Author(s):  
A. DiCarlo ◽  
H. T. Y. Yang ◽  
S. Chandrasekar
Keyword(s):  
A Priori ◽  
Model Material ◽  
Material Behavior ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Indentation Tests ◽  
Strain Relationship ◽  
Initial Force ◽  
Relationship Of ◽  
Force Displacement

A method for determining the stress–strain relationship of a material from hardness values H obtained from cone indentation tests with various apical angles is presented. The materials studied were assumed to exhibit power-law hardening. As a result, the properties of importance are the Young's modulus E, yield strength Y, and the work-hardening exponent n. Previous work [W.C. Oliver and G.M. Pharr, J. Mater. Res. 7, 1564 (1992)] showed that E can be determined from initial force–displacement data collected while unloading the indenter from the material. Consequently, the properties that need to be determined are Y and n. Dimensional analysis was used to generalize H/E so that it was a function of Y/E and n [Y-T. Cheng and C-M. Cheng, J. Appl. Phys. 84, 1284 (1999); Philos. Mag. Lett. 77, 39 (1998)]. A parametric study of Y/E and n was conducted using the finite element method to model material behavior. Regression analysis was used to correlate the H/E findings from the simulations to Y/E and n. With the a priori knowledge of E, this correlation was used to estimate Y and n.

Analysis of a Nonlinear Dynamic Vibration Absorber

1953 ◽  
Vol 20 (4) ◽  
pp. 515-518
Author(s):  
L. A. Pipes
Keyword(s):  
Forced Oscillations ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Nonlinear Characteristics ◽  
Disturbing Force ◽  
Main Mass ◽  
Dynamic Vibration ◽  
Nonlinear Force ◽  
Linear Spring ◽  
Force Displacement

Abstract This paper presents a mathematical analysis of the action of a dynamic vibration absorber. The system analyzed consists of a main mass attached to a rigid foundation by a linear spring coupled to the absorber mass by a spring of nonlinear characteristics. The forced oscillations of the system produced by a harmonic disturbing force acting on the main mass are studied analytically. It is assumed that the coupling absorber spring has nonlinear force-displacement characteristics of the hyperbolic sine type. Expressions for the amplitudes of the vibrations of the two masses as functions of the frequency of the disturbing force are obtained.

Dynamics of Deformable Fractal Surface in Contact with Harmonically Excited Rigid Flat

2017 ◽  
Vol 7 (2) ◽  
pp. 38-62
Author(s):  
Tamonash Jana ◽  
Anirban Mitra ◽  
Prasanta Sahoo
Keyword(s):  
Rough Surface ◽  
Dynamic Properties ◽  
Element Model ◽  
Harmonic Excitation ◽  
System Response ◽  
Fractal Surface ◽  
Fractal Rough Surface ◽  
Mass Damper ◽  
Relationship Of ◽  
Force Displacement

Dynamics of contact between a deformable fractal rough surface and a rigid flat is studied under harmonic excitation to the flat surface. Fractal surface is generated from the modified Weierstrass-Mandelbrot function and is imported to ANSYS to construct the finite element model of the same. A parameter called ‘nonlinearity exponent', is obtained from the force-displacement relationship of the rough surface and is used to find out the dynamic properties of the contacting interface using single spring-mass-damper model. The effect of variation in surface roughness and material properties on the system response is analyzed. The system exhibits superharmonic responses for different values of the nonlinearity exponent. The phase plot and time-displacement plots for the system are also furnished.

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