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Simplified single plate connection designsEl-Salti, Maher Kh., 1960- January 1988 (has links)
A simplified procedure that results in a significant reduction of the computation time and effort in the design of single plate framing connections is presented herein. This simplified method is based upon the current design procedure which is applicable to partially restrained shear connections. A total of 140 steel beams with 700 analyses and 500 composite beams were used to develop the simplified method. Tables are provided for the design of most commonly used connections. The simplified single plate design is applicable for fully tightened 3/4, 7/8, and 1. inch A325 or A490 bolts used in either standard round or slotted holes, or snug tight A325 or A490 bolts in standard holes. These studies have led to a single table of the restraint design moments which greatly simplifies the design procedure.
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Ultrasonic techniques for adhesive bond examination of production automotive structuresWeise, Victoria Louise January 1998 (has links)
No description available.
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The mechanical failure of articular cartilageKerin, Alexander James January 1998 (has links)
No description available.
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Multijoint arm movements: Predictions and observations regarding initial muscle activity at the shoulder and elbow.Karst, Gregory Mark. January 1989 (has links)
Understanding the control strategies that underlie multijoint limb movements is important to researchers in motor control, robotics, and medicine. Due to dynamic interactions between limb segments, choosing appropriate muscle activations for initiating multijoint arm movements is a complex problem, and the rules by which the nervous system makes such choices are not yet understood. The aim of the dissertation studies was to evaluate some proposed initiation rules based on their ability to correctly predict which shoulder and elbow muscles initiated planar, two-joint arm movements in various directions. Kinematic and electromyographic data were collected from thirteen subjects during pointing movements involving shoulder and elbow rotations in the horizontal plane. One of the rules tested, which is based on statics, predicted that the initial muscle activity at each joint is chosen such that the hand exerts an initial force in the direction of the target, while another rule, based on dynamics, predicted initial muscle activity such that the initial acceleration of the hand is directed toward the target. For both rules, the data contradict the predicted initial shoulder muscle activity for certain movement directions. Moreover, the effects of added inertial loads predicted by the latter rule were not observed when a 1.8 kg mass was added to the limb. The results indicated, however, that empirically derived rules, based on ψ, the target direction relative to the distal segment, could predict which muscles would be chosen to initiate movement in a given direction. Furthermore, the relative timing and magnitude of initial muscle activity at the shoulder and elbow varied systematically with ψ. Thus, the target direction relative to the forearm may be an important variable in determining initial muscle activations for multijoint arm movements. These findings suggest a control scheme for movement initiation in which simple rules suffice to launch the hand in the approximate direction of the target by first specifying a basic motor output pattern, then modulating the relative timing and magnitude of that pattern.
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Corrosion fatigue and fracture mechanics of weldable high strength jack up steelsMyers, Peter January 1998 (has links)
No description available.
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The application of texture discrimination to SMT QFP solder joint inspectionWang, Jia-Chang January 1998 (has links)
No description available.
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Fusion welding of crosslinked polyethyleneOvington, Stephen January 1995 (has links)
No description available.
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Elastic-plastic generalised load-displacement prediction for tubular jointsLeen, Sean B. January 1999 (has links)
No description available.
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A theoretical study of the strength of perfect and imperfect interfaces between dissimilar materialsKelly, Piaras January 1992 (has links)
No description available.
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Development of data sets on joint characteristics and consideration of associated instability for a typical South African mineGumede, Hlangabeza 26 February 2007 (has links)
Student Number : 0400188H -
MSc(Eng) Dissertation -
School of Mining -
Faculty of Engineering and the Built Environment / The occurrence of fracturing due to high stress levels is a major factor with regard
to hangingwall stability in deep level gold mine stopes. However, rock falls
cannot be the result of these fractures alone. Blocks in the hangingwall strata must
be defined by a combination of the stress induced fractures and naturally
occurring geological planes of weakness. These planes include bedding planes
and joint planes. The importance of the natural joints and bedding planes in
defining the instability has not been given the attention that it deserves, to the
extent that there are apparently no documented, published data available on joint
set characteristics. This is perhaps an indication that such data do not exist on the
mines. To remedy this situation, detailed scan-line joint mapping exercises have
been carried out in several geological environments in two gold mines. The joint
data collected on joint geometry included orientation, spacing and length. The
results presented in this dissertation are believed to be the first such data available
on jointing in gold mines. The main conclusions from the interpretation of these
data are that there are two dominant joint sets in stope hangingwalls and at least
one of these sets is shallow dipping. In development tunnels there is one
predominant set of shallow dipping bedding planes. Both in stope hangingwalls
and in development tunnels, steeply dipping random joints constitute half of the
mapped joints.
The statistical joint data obtained was used to investigate and analyse the potential
for rock falls in stopes. This involved the prediction of characteristic block
parameters such as expected block sizes and rock fall thicknesses. These
predictions show good agreement with measurements made of actual rockfalls
(generic results). Most unstable blocks in stope hangingwalls are less than a cubic
meter in size. These blocks are more likely to fall between support elements than
fail the supports, whilst failure of the fewer large blocks (20%) usually involves
failure of support elements. It is concluded that failure probabilities are largely
related to joint geometry. Common failure modes for small blocks are single plane sliding and ‘dropping out’ whilst larger blocks usually fail by rotation. The study
increases understanding of rock fall mechanisms and the support-block
interaction. The results of the analyses of block stability that have been reported in
this dissertation show disturbingly high probabilities of failure in the stope face
area (or working area), particularly for blocks that are smaller than about 1.5 cubic
metres in size.
The study has demonstrated the important influence that natural joints have on
hangingwall block stability, and the importance of joint mapping to produce
statistical joint data that can be used in the assessment of stability against rock
falls. Although joint mapping may be a tedious exercise in mines, it has been
shown to give similar results regarding heights of rock falls to that interpreted
from collection of empirical incident and accident record data over a ten-year
period. It is considered that this could provide good input data for the design of
stope support.
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