Response of a flexible tube to transverse impact II. Numerical and experimental results

Wave Motion ◽  
1991 ◽  
Vol 13 (1) ◽  
pp. 1-12
Author(s):  
Zongping Luo ◽  
Tomoaki Kurokawa ◽  
Werner Goldsmith ◽  
Jerome L. Sackman
1951 ◽  
Vol 165 (1) ◽  
pp. 176-188 ◽  
Author(s):  
D. G. Christopherson

In this paper the problem of transverse impact on a uniform beam is considered theoretically. Two examples which can be taken as representing a wide range of impacts which occur in practice are referred to particularly: (1) the beam struck transversely by a uniform square-ended rod travelling perpendicularly to it; (2) the same problem for the striker having a spherical end. In these examples it is shown that the ability of the beam to deflect in shear as well as in bending plays a dominant part in what takes place, and that, as far as the force between striker and beam is concerned, the length of the beam is usually without importance, as there is not time during the impact for an elastic wave to travel to the ends of the beam and return. It is shown that in regard to example (2) the theory presented is in good agreement with Arnold's experimental results obtained some years previously, and curves are given from which the maximum force between beam and striker can be obtained in terms of three parameters, representing respectively the velocity, the mass, and the radius of the striker, each dependent on the ratio of shear stiffness to bending stiffness for the beam.


Wave Motion ◽  
1990 ◽  
Vol 12 (6) ◽  
pp. 595-605 ◽  
Author(s):  
Zongping Luo ◽  
Tomoaki Kurokawa ◽  
Werner Goldsmith ◽  
Jerome L. Sackman

1993 ◽  
Vol 23 (3) ◽  
pp. 191-204 ◽  
Author(s):  
Scott R. Finn ◽  
Ye-Fei He ◽  
George S. Springer

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Tonghui Tian ◽  
Jiehong Yuan ◽  
Daokui Li ◽  
Qingwen Wang ◽  
Baisheng Chen

Based on the bolted flange connection structure between stages of the missiles, four experimental specimens are simplified and manufactured, and the transverse impact failure experiments of the drop hammer are designed and carried out in this study. During the experiments, a new signal sensor is designed to collect the data of the bolts force, and the response data such as the bolts force, the slotted displacement of the connecting interface, and the impact force are collected in the loading process. The sequential failure mechanism of the structure under transverse impact load is analyzed and demonstrated according to the experimental results and the measured data. Additionally, a finite element model to simulate the failure process of the connection structure has been established, and the precision of the model has been verified and validated according to the experimental results. Moreover, the comparison between the results of the experiments and the simulation shows that the precision of this model is reliable in the engineering.


1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.


Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.


Author(s):  
A. Ourmazd ◽  
G.R. Booker ◽  
C.J. Humphreys

A (111) phosphorus-doped Si specimen, thinned to give a TEM foil of thickness ∼ 150nm, contained a dislocation network lying on the (111) plane. The dislocation lines were along the three <211> directions and their total Burgers vectors,ḇt, were of the type , each dislocation being of edge character. TEM examination under proper weak-beam conditions seemed initially to show the standard contrast behaviour for such dislocations, indicating some dislocation segments were undissociated (contrast A), while other segments were dissociated to give two Shockley partials separated by approximately 6nm (contrast B) . A more detailed examination, however, revealed that some segments exhibited a third and anomalous contrast behaviour (contrast C), interpreted here as being due to a new dissociation not previously reported. Experimental results obtained for a dislocation along [211] with for the six <220> type reflections using (g,5g) weak-beam conditions are summarised in the table below, together with the relevant values.


Author(s):  
Scott Lordi

Vicinal Si (001) surfaces are interesting because they are good substrates for the growth of III-V semiconductors. Spots in RHEED patterns from vicinal surfaces are split due to scattering from ordered step arrays and this splitting can be used to determine the misorientation angle, using kinematic arguments. Kinematic theory is generally regarded to be inadequate for the calculation of RHEED intensities; however, only a few dynamical RHEED simulations have been attempted for vicinal surfaces. The multislice formulation of Cowley and Moodie with a recently developed edge patching method was used to calculate RHEED patterns from vicinal Si (001) surfaces. The calculated patterns are qualitatively similar to published experimental results and the positions of the split spots quantitatively agree with kinematic calculations.RHEED patterns were calculated for unreconstructed (bulk terminated) Si (001) surfaces misoriented towards [110] ,with an energy of 15 keV, at an incident angle of 36.63 mrad ([004] bragg condition), and a beam azimuth of [110] (perpendicular to the step edges) and the incident beam pointed down the step staircase.


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