Showing papers on "Embedment published in 1979"
Patent•
20 Apr 1979
TL;DR: In this article, a locking fastener such as a threaded nut, bolt or screw includes a body portion with a flange at the workpiece engaging end defining a bearing surface, which is rendered rigid by brace structure associated with the body portion of the fastener.
Abstract: A locking fastener such as a threaded nut, bolt or screw includes a body portion with a flange at the workpiece engaging end defining a bearing surface. Segments of the flange are rendered rigid by brace structure associated with the body portion of the fastener. Locking teeth project from the bearing surface in resilient segments of the flange located between the rigid segments. Upon tightening of the fastener against a workpiece, substantial clamp loads are imposed by the rigid flange segments while engagement of the teeth with the workpiece causes axial deflection of the resilient segments so that loss of clamp load and decrease in release torque due to tooth embedment is prevented.
24 citations
Abstract: A time domain finite element method has been used to investigate the response to seismic waves of rigid, three-dimensional, embedded foundations The method eliminates the influence of artificial grid boundaries by completing the transient solution prior to the arrival of any nonphysical reflections The accuracy of the numerical procedure has been examined by comparison with analytic solutions; discrepancy is less than 5% at all frequencies up to β/a in which β=the shear wave speed of the embedment medium; and a is the foundation radius For a hemispherical foundation, the scattering of vertically incident S waves reduces the higher frequency horizontal translation of the foundation compared with the free-field motion but introduces a significant rocking component that is absent from the free field
22 citations
TL;DR: Experimental tests demonstrate that there is a sharp drop in resistance to fatigue fracture when the grain size is increased from 75 to 150 micrometers, which is at least a partial explanation for fatigue fractures of the stems of total hip-joint prostheses reported in the literature.
Abstract: Experimental tests demonstrate that there is a sharp drop in resistance to fatigue fracture when the grain size is increased from 75 to 150 micrometers. This is at least a partial explanation for fatigue fractures of the stems of total hip-joint prostheses reported in the literature. It is also shown that plastic strains associated with fatigue stressing increase with increasing grain size so that loosening of the bone cement embedment may also be part of the premature failure process.
8 citations
01 Jan 1979
TL;DR: In this article, a series of centrifuge experiments were conducted on very flexible model pipes buried at shallow depth in uniform dense sand, to examine the validity of ring compression theory under the combined action of self weight of the backfill and surface loading.
Abstract: The report covers work carried out in the Cambridge university engineering department under a transport and Road Research Laboratory research contract to study the behaviour of buried flexible pipes. The work consists of a series of centrifuge experiments conducted on very flexible model pipes buried at shallow depth in uniform dense sand, to examine the validity of ring compression theory under the combined action of self weight of the backfill and surface loading. Tests were carried out on model pipes made from steel and plastic having different effective stiffness to study the influence of this factor on the reductions in load which takes place due to arching. A comparison is given of the calculated pressures and measured pipe stresses from which load reduction factors are derived. The ring compression theory is shown to be valid for model pipes in wide trenches or under embankments when subjected to combined surface and backfill loadings. The results illustrate that the load reduction factor is influenced by the intensity of surface loading and by the depth of embedment and is greatly dependent on the effective stiffness of the pipe.(a) (TRRL)
8 citations
01 Jan 1979
5 citations
01 Jan 1979
TL;DR: In this paper, a nominal 300k lb propellant actuated embedment anchor was built and tested in common sediments and corals, and the complete anchor weighing 4 1/2 tons was recovered.
Abstract: Recently a nominal 300K lb propellant actuated embedment anchor was built. It is designed to provide capacities of 380K lb to 600K lb in common sediments and corals. The complete anchor weighing 4--1/2 tons, is recovered. Their capacity to resist uplift, rapid installation, lightweight line compatibility, and capability to function in coral as well as sediments make these anchors attractive for supply vessel moorings, tension legs, and construction moorings.
4 citations
Journal Article•
1 citations
TL;DR: In this paper, the dynamic response of strip footings resting on a soil medium, idealized as an elastic halfspace, is obtained using the finite element discretization technique with constant strain rectangular elements consisting of 4CST elements.
Abstract: Dynamic response of strip footings resting on a soil medium, idealized as an elastic halfspace, is obtained using the finite element discretization technique with constant strain rectangular elements consisting of 4CST elements. Boundary stresses have been computed using a combination of Rayleigh wave absorbing boundaries (RAB) and standard vicous boundaries (SVB). The influences of contact pressure distributions at the footing—soil interface, mass and frequency ratios on the dynamic response of a strip footing are studied. Effects of embedment, static surcharge, nonhomogeneity and nonlinear constitutive relations are shown. Results are compared with the existing solution and are presented graphically.