Static displacement expansion for cable-strut tensile structures by concurrently using mode compensation and optimization strategies

Author(s):  
Xiaoshun Wu ◽  
Chen-hui Huang ◽  
Jun Ma ◽  
Tommy H.T. Chan
Keyword(s):  
Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Yuan Wang ◽  
Chenglong Wu ◽  
Yuntian Zhou

A systematic numerical method was presented to investigate the effect of aperture distribution on the relation of capillary pressure versus fluid saturation (P-S relation) for a single fracture. The fracture was conceptualized as a two-dimensional lattice-grid model and its aperture field was described by a probability distribution. Based on the invasion percolation theory, a program was developed to simulate the quasi-static displacement. The simulation was verified validly by comparisons of the experimental results. The effects of the statistical parameters were further quantified. The results show that the largest local aperture on the fracture boundary determines the AEV. The larger mean decreases the variation coefficient, which causes the more uniform aperture field, smoother air invasion front, and steeper capillary pressure-saturation curve (CPSC). The larger standard deviation increases not only the range but also the contrast degree of the apertures, thus providing a nondeterministic rule in the P-S relation. The larger correlation length causes a more homogeneous aperture field and a dual connectivity of the fracture. The increase of the difference and contrast degree between the small and large apertures results in dual-aperture fields. The dual-aperture field and dual connectivity of the fracture both contribute to the bimodal characteristic of the CPSC.


2010 ◽  
Vol 452-453 ◽  
pp. 129-132
Author(s):  
Paola Antonaci ◽  
Pietro G. Bocca ◽  
Davide Masera

The paper presents the results of an experimental investigation conducted on bricks. Prism-shaped specimens were produced. Laboratory tests were carried out at the Non-Destructive Testing Laboratory of the Politecnico di Torino. They were subjected to static compressive tests for the determination of their mechanical properties and cyclic compressive tests for the analysis of their fatigue behaviour. The aim of this work is to apply a failure criterion based on the observation of the static and cyclic curves to estimate the fatigue life and the long-term behaviour of the brick. Subsequently, it will be possible to give a relation between the static-displacement and cyclic-displacement of the material tested.


2018 ◽  
Vol 185 ◽  
pp. 09005
Author(s):  
V.M. Polunin ◽  
P.A. Ryapolov ◽  
E.V. Sheldeshova

Measurements and theoretical analysis of the processes of static displacement and oscillations of the magnetic fluid column confined by magnetic levitation in a strong magnetic field in a horizontally placed tube are carried out. The calculations of the saturation magnetization, made on the basis of the obtained results of the displacement and the oscillation frequency for the sample of the magnetic fluid under study, are in good agreement with the experimental data. The described technique is of interest when studying saturation magnetization, magnetophoresis, aggregation of nanoparticles and their temporal dependence in magnetic colloids.


Author(s):  
Hanen Jrad ◽  
Jean Luc Dion ◽  
Franck Renaud ◽  
Imad Tawfiq ◽  
Mohamed Haddar

Viscoelastic components are incorporated into automobile and aerospace structures system in order to damp mechanical vibrations. Viscoelastic components are a key element in designing desired dynamic behaviour of mechanical systems. Viscoelastic components dynamic characteristics are often very complex, due to the dependence of its response on several variables, such as frequency, amplitude, preload, and temperature. These dependencies can be critical in capturing the mechanical proprieties and so non linear dynamical behaviour may appear. Assuming that non linearities are due to non linear elasticity, the non linear Generalized Maxwell Model (GMM) is proposed to characterize dynamics of viscoelastic components. Parameters of GMM are identified from Dynamic Mechanical Analysis (DMA) tests for different excitation frequencies. A particular result from identification is that the non linear stiffness is dependent upon displacement amplitude and static displacement under static preload. The significance of this result is that the non linear dynamics of the viscoelastic component can be represented by a simple analytical model capable to produce accurate results. Comparison between measurements and simulations of dynamic stiffness of viscoelastic component has been carried on.


2003 ◽  
Vol 17 (08n09) ◽  
pp. 1349-1354
Author(s):  
Moon Sik Han ◽  
Jae Ung Cho ◽  
Ouk Sub Lee

In this paper, computer simulations of the mechanical behavior of 3 point bend (3PB) specimens with a quarter notch under impact load are performed. The cases with various impact velocities applied at the side of the specimen are considered. An elastic-plastic von Mises material model is chosen. Results from no viscoplastic and viscoplastic materials are compared. Their materials are applied with static displacement speed and various impact velocities. The configuration of the specimen has the reduced width at the ends. This modified 3PB specimen design has been studied in order to avoid the initial compressive load of the crack tip and also to avoid the uncertain boundary conditions at the impact heads.


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