scholarly journals Mechanical Failure Mode of Metal Nanowires: Global Deformation versus Local Deformation

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Duc Tam Ho ◽  
Youngtae Im ◽  
Soon-Yong Kwon ◽  
Youn Young Earmme ◽  
Sung Youb Kim
Author(s):  
Bo Wang ◽  
Yung-Sup Shin ◽  
Eric Norris

The objective of this study is to investigate the relationship between the maximum allowable hull deformation, which includes global elongation and local deflection, and the capacity of the CCS in membrane-type LNG vessels. The LNG CCS mainly consists of the primary barrier (e.g. a corrugated membrane for GTT MK III system and an invar membrane for GTT NO 96 system) and the insulation panel which is attached to the inner hull through mastics or couplers. The excessive hull elongation due to dynamic wave loads may cause fatigue damage of the primary barrier. Thus, the maximum allowable hull elongation (global deformation) can be determined based on the fatigue strength of the primary barrier. On the other hand, the excessive hull deflection due to cargo or ballast water pressure may cause failure of the insulation panel and the mastic. Therefore, the maximum allowable hull deflection (local deformation) in the hull design can be determined based on the strength of the insulation panel and the mastic. In the present paper, the determination of fatigue life vs. strain curves of materials has been summarized for the primary barrier. Fatigue curves based on either structural fatigue tests or standard specimen tests can be applied in fatigue assessment of a primary barrier. As an example, the finite element (FE) analysis has been conducted on the MK III CCS with the hull structure under pressure loads. Two different load cases including full load and ballast load conditions have been considered to evaluate the structural integrity of the insulation system in numerical simulations. FE results show that the mechanical behavior of the insulation system and the mastic under the maximum allowable hull deflection has been examined based on the yielding strength of each individual component. Finally, the complete procedure to determine the maximum allowable hull elongation and the maximum allowable hull deflection has been developed for meeting the requirements of containment system design for membrane-type LNG carriers.


1999 ◽  
Vol 1999 (509) ◽  
pp. 199-236 ◽  
Author(s):  
Gebhard Böckle

Abstract Given an absolutely irreducible Galois representation : GE → GLN (k), E a number field, k a finite field of characteristic l > 2, and a finite set of places Q of E containing all places above l and ∞ and all where ∞ ramifies, there have been defined many functors representing strict equivalence classes of deformations of such a representation, e.g. by Mazur or Wiles in [15] or [26], with various conditions on the behaviour of the deformations at the places in Q and with the condition that the deformations are unramified outside Q. Those functors are known to be representable. For as above, our goal is to present a rather general class of global deformation functors that satisfy local deformation conditions and to investigate for those, under what conditions the global deformation functor is determined by the local deformation functors. We will give precise conditions under which the local functors for all places in Q are sufficient to describe the global functor, first in a coarse form, then in a refined form using auxiliary primes as done by Taylor and Wiles in [24]. This has several consequences. The strongest is that one can derive ring theoretic results for the universal deformation space by Mazur if one uses results of Diamond and Wiles, cf. [11] and [26], and if one has a good understanding of all local situations. Furthermore it is easier to understand what happens under increasing the ramification as done by Boston and Ramakrishna in [6] and [20], [21]. Finally we shall reinterpret the results in the case of a tame representation by directly considering presentations of certain pro-l Galois groups and revisiting the prime-to-adjoint principle of Boston, cf. [5].


Author(s):  
R. S. Hwang ◽  
E. J. Haug

Abstract Formulations of translational kinematic constraints between flexible bodies are developed to model deformatioin of flexible surfaces that move relative to one another. Three types of flexible translational articulated joints are presented The joint formulations are illustrated in analysis of prototype systems with translational joints. Global deformation modes and substructure local deformation modes are used and compared in numerical examples.


2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Agustin Dwi Sumiwi ◽  
Efi Afrizal ◽  
Jaswar Jaswar ◽  
Handayanu Handayanu

This paper discusses graded and collision velocity supply vessel influence to local and global structure damage subject to collision. This case study for CONOCO BELANAK wellhead platform that approaching with of 2500 tonnes of supply vessel with tidal variation for each collision scenario. Deformation of the jacket leg occurs causes by material inability to proof against pressure. This paper uses 2 software are ANSYS LS-DYNA 9.0 to acquire local deformation and GT-STRUDL 27.0 version to acquire global deformation included dynamic transient analysis. Outside diameter of Jacket Leg is 1.651 m with wall thickness is 0.0381 m. Normal velocity in each sideway, stern; manoeuvring collision and extreme velocity is 0.28 m/s, 0.39 m/s and 0.74. Extreme velocity in each sideway and stern collision is and 10% exceedance velocity is 0.54 m/s, 0.73 m/s and 1.29 m/s. The result of this paper is dent of the landing platform for each normal and extreme is 0.2725 m, 0.2352 m, and 0. 3241 m/s it must be repaired or changed because of it is 30% larger than spacing frame. Maximum displacement x, y, z direction is 0.2423 m on 0.38 s, 0. 0559 m on 0.39 s, 0.7492 m on 0.41 s. The deformation in landing platform, jacket leg and jacket structure is smaller than research result indeed.


2015 ◽  
Vol 61 (1) ◽  
pp. 74-85 ◽  
Author(s):  
Matej Biček ◽  
Gorazd Gotovac ◽  
Damijan Miljavec ◽  
Samo Zupan

2014 ◽  
Vol 5 ◽  
pp. 822-836 ◽  
Author(s):  
Dave Maharaj ◽  
Bharat Bhushan

Nanoscale research of bulk solid surfaces, thin films and micro- and nano-objects has shown that mechanical properties are enhanced at smaller scales. Experimental studies that directly compare local with global deformation are lacking. In this research, spherical Au nanoparticles, 500 nm in diameter and 100 nm thick Au films were selected. Nanoindentation (local deformation) and compression tests (global deformation) were performed with a nanoindenter using a sharp Berkovich tip and a flat punch, respectively. Data from nanoindentation studies were compared with bulk to study scale effects. Nanoscale hardness of the film was found to be higher than the nanoparticles with both being higher than bulk. Both nanoparticles and film showed increasing hardness for decreasing penetration depth. For the film, creep and strain rate effects were observed. In comparison of nanoindentation and compression tests, more pop-ins during loading were observed during the nanoindentation of nanoparticles. Repeated compression tests of nanoparticles were performed that showed a strain hardening effect and increased pop-ins during subsequent loads.


2008 ◽  
Vol 389-390 ◽  
pp. 404-409
Author(s):  
Masayuki Nunobiki ◽  
Koichi Okuda ◽  
Shogo Morino

When many products were cut out from a wide base sheet by laser cutting in some conditions, an error occurred in a height regulator by the sheet's greatly bending. It is necessary to avoid occurring the error at unmanned processing. We paper investigated local deformation around cutting edge. The cutting path consists of piercing point, terminal point, straight lines, cranks and curves. We measured local deformation around terminal point, crank and straight line. It was clarified that base sheet bent greatly around terminal points and crank and the sheet curved gradually along the straight line. We investigated relationship between global deformation of the base sheet and the local deformation. It was able to presume the entire deformation of base sheet by overlapping the individual deformations around cutting edge.


2013 ◽  
Vol 18 (2) ◽  
pp. 81-87
Author(s):  
Steven J. Ziegenfuss ◽  
Amy F. Helgerson ◽  
Bethzayda Matos ◽  
Anne M. Dombroski-Brokman

Author(s):  
JIANHUA YAO ◽  
RUSSELL TAYLOR

In this paper we present a novel technique for non-rigid medical image registration and correspondence finding based on a multiple-layer flexible mesh template matching technique. A statistical anatomical model is built in the form of a tetrahedral mesh, which incorporates both shape and density properties of the anatomical structure. After the affine transformation and global deformation of the model are computed by optimizing an energy function, a multiple-layer flexible mesh template matching is applied to find the vertex correspondence and achieve local deformation. The multiple-layer structure of the template can be used to describe different scale of anatomical features; furthermore, the template matching is flexible which makes the correspondence finding robust. A leave-one-out validation has been conducted to demonstrate the effectiveness and accuracy of our method.


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