Embedment

About: Embedment is a research topic. Over the lifetime, 2441 publications have been published within this topic receiving 31444 citations.

In Situ Measurement of the Dynamic Penetration of Free-Fall Projectiles in Soft Soils Using a Low-Cost Inertial Measurement Unit

Abstract: Six degree-of-freedom motion data from projectiles free-falling through water and embedding in soft soil are measured using a low-cost inertial measurement unit, consisting of a tri-axis accelerometer and a three-component gyroscope. A comprehensive framework for interpreting the measured data is described and the merit of this framework is demonstrated by considering sample test data for free-falling projectiles that gain velocity as they fall through water and self-embed in the underlying soft clay. The paper shows the importance of considering such motion data from an appropriate reference frame by showing good agreement in embedment depth data derived from the motion data with independent direct measurements. Motion data derived from the inertial measurement unit are used to calibrate a predictive model for calculating the final embedment depth of a dynamically installed anchor.

Comment on "The properties of free polymer surfaces and their influence on the glass transition temperature of thin polystyrene films" by J.S. Sharp, J.H. Teichroeb and J.A. Forrest.

Abstract: Sharp, Teichroeb and Forrest [J.S. Sharp, J.H. Teichroeb, J.A. Forrest, Eur. Phys. J. E 15, 473 (2004)] recently published a viscoelastic contact mechanics analysis of the embedment of gold nanospheres into a polystyrene (PS) surface. In the present comment, we investigate the viscoelastic response of the surface and conclude that the embedment experiments do not support the hypothesis of a liquid surface layer of sufficiently reduced “rheological temperature” to explain reports of very large reductions in the glass temperature of freely standing ultrathin polystyrene films. We also report some errors and discrepancies in the paper under comment that resulted in an inability to reproduce the reported calculations. We present our findings of error in a spirit of clarifying the problem of embedment of spheres into surfaces and in order that others can understand why they may not reproduce the results reported by Sharp, Teichroeb and Forrest. In the comment, we also examine the effects of the magnitude of the forces that result from the polymer surface-nanosphere particle interactions on the viscoelastic properties deduced from the embedment data and we provide a comparison of apparent surface or “rheological” temperature vs. experimental temperature that indicates further work needs to be performed to fully understand the surface embedment experiments. Finally, we comment that the nanosphere embedment measurements have potential as a powerful tool to determine surface viscoelastic properties.

Capacity of dynamically embedded plate anchors as assessed through field tests

Abstract: A dynamically embedded plate anchor (DEPLA) is a rocket-shaped anchor that penetrates to a target depth in the seabed by the kinetic energy obtained through free-fall and by the anchor’s self-weight. After embedment, the central shaft is retrieved leaving the anchor flukes vertically embedded in the seabed. The flukes constitute the load bearing element as a plate anchor. This paper presents and considers field data on the embedment depth loss due to the plate anchor keying process and the subsequent bearing capacity factor of the plate anchor element. The loss in plate anchor embedment was significantly higher than that reported from corresponding centrifuge tests and is reflected in the larger padeye displacements required to mobilize peak capacity in the field tests. Measured plate capacities and plate rotations during keying indicate that the end of keying coincides with the peak anchor capacity. Experimental bearing capacity factors are in the range Nc = 14.3–14.6, which is appreciably higher than ex...