An Analytical and Experimental Study to Develop a Nonmechanical System to Induce Resonance in a Rod Drill for Frozen Soil

The objective was to investigate nonmechanical methods for inducing longitudinal resonant vibrations in a rod which could serve as a drill for frozen soil and to select the most promising method for further development. An analytical model of the mechanics of the vibratory drill was developed to det...

Full description

Bibliographic Details
Main Author: Goldstein, Seth R
Other Authors: FOSTER-MILLER INC WALTHAM MA
Format: Text
Language:English
Published: 1969
Subjects:
Snow
Ice and Permafrost
Hydraulic and Pneumatic Equipment
Machinery and Tools
Mechanics
*DRILLS
*RODS
*SOILS
ANCHORS(STRUCTURAL)
DRILLING
DRILLING MACHINES
FEASIBILITY STUDIES
FREEZING
HYDRAULIC ACTUATORS
HYDRAULIC PRESSURE PUMPS
MAGNETOSTRICTIVE ELEMENTS
MATHEMATICAL MODELS
PERMAFROST
PIEZOELECTRIC TRANSDUCERS
PULSE GENERATORS
RELIABILITY
RESONANT FREQUENCY
ROTARY VALVES
TENTS
VIBRATION
VIBRATORS(MECHANICAL)
WEIGHT
SOILS
TENT STAKES
Ice
permafrost
Online Access:http://www.dtic.mil/docs/citations/AD0866898
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0866898
Description
Summary:The objective was to investigate nonmechanical methods for inducing longitudinal resonant vibrations in a rod which could serve as a drill for frozen soil and to select the most promising method for further development. An analytical model of the mechanics of the vibratory drill was developed to determine the exciter output requirements. A large number of exciter concepts were conceived and evaluated. The major conclusion is that a hydraulic exciter system is the best overall concept for meeting the exciter output requirements, and its feasibility has been established both analytically and experimentally. Piezoelectric and magnetostrictive transducers are also feasible but are less desirable than hydraulic systems when weight, durability, safety, cost, and other factors are considered. Unstable bearings, electromagnetic devices, and various other concepts were examined and rejected for reasons of low efficiency and excessive size. The best application of the hydraulic exciter concept utilizes a rotary valve to control flow to a piston-type actuator that is rigidly attached to the drill rod. A laboratory model of this type of exciter was designed, built, and tested to demonstrate the hydraulic excitation principle. The model system, which used a 6-foot long steel drill rod, exhibited a resonant amplitude peaking of four at a frequency of 1425 cps.

Similar Items