Yan F.,Harbin Engineering University |
Zhang C.,Harbin Engineering University |
Sun L.,Harbin Engineering University |
Zhang D.,DMAR Engineering Inc.
Journal of Coastal Research | Year: 2015
The real impact of water or waves on coastal and ocean engineering infrastructures is anticipated to be significant. It is a complicated problem to couple a deformable structure with an air water fluid flow. The paper studies the slamming pressure and hydroelastic vibration of a flat plate by a series of drop tests. The peak pressure and related air-water status are recorded simutaneously. Part of the real physical field is revealed for future numerical model of strong interaction with fluid-solid system. It is found that a thin layer of air, which is enclosed by water raised up at both ends, is trapped into the interface of the plate and water. The peak pressure occurs at the plate center and keeps steady in repetitive tests. Hydroelastic vibration, which was stimulated by impacting load, makes the pressure to decrease periodically in a turbulent air-water field. Characteristic frequency of pressure signals agrees with the wet modes of the plate. © 2015 Coastal Education and Research Foundation, Inc. Source
DMAR Engineering Inc. | Date: 2014-07-22
Apparatus and methods related to flow rate testing are described. For example, some embodiments may contain a hydraulic power unit, a flow meter, a pressure gauge, an accelerometer, a reservoir containing testing fluid, two fitting connections, and hoses for interconnecting the components in a closed loop, for testing flow rate through a tube and pinpointing the obstruction location inside the tube.
DMAR Engineering Inc. | Date: 2014-09-29
Apparatus and methods related to damping testing are disclosed. For example, some embodiments may contain a testing platform supported on wheels and moveable by hydraulic cylinders, and two fasteners for fastening the testing sample, one fixed on the testing platform and the other moveable along the testing platform by another hydraulic cylinder, and may be used for the damping testing of slender structures such as umbilicals and flexibles used in oil and gas underwater field development.
DMAR Engineering Inc. | Date: 2014-05-24
Apparatus and methods related to pipeline freespan support are described. For example, some embodiments may contain an upper structure, which contains at least four legs connected to one another by a number of bracing members, and a number of attachment points through which the upper structure can be lifted, and a lower structure, which contains at least four posts that can be connected to, and disconnected from as needed, the four legs of the upper structure, two spaced mud mats on which the posts stand, and at least two horizontal arms that can be attached to the posts, rotate about the posts, connect to and be locked with the posts on the other mud mat, and be lifted to an appropriate height to provide suitable support at the pipeline freespan location.
DMAR Engineering Inc. | Date: 2014-06-03
Apparatus and methods related to catenary riser testing are described. For example, some embodiments may contain a ground platform, elevated deck, a catenary-shaped testing sample, a fixed clamp on one end of the testing sample and a rotatable clamp on the other end of the testing sample, and a plurality of hydraulic cylinders for controlling the vertical and horizontal positions and motions of the elevated deck and the positions and rotations of the rotatable clamp, for analyzing the characteristics of the testing sample, such as its touchdown point dynamic motions and stresses.