Dynamics Analysis And Dynamic Design Research On The Drilling Rod Device Of New Screw Pile Hammers

The new screw pile hammers is designed and developed by Hainan Zhuodianhigh-tech co., LTD., Wuhan University of Technology&Wuchang shipbuildingindustry co., LTD which is a new screw-plug pile driver. The pile machine get highlymarket welcome due to without removal of soil and stability combined with soilcompared with the traditional pile drivers.The drilling rod device of the new screw pile hammers is one of the importantdevice in the drilling system, the influence of vibration impact during the time ofprocess of construction often makes wear and fracture failure and cause hugeeconomic loss.The dynamics behavior is very complex of the drilling rod device of the newscrew pile hammers during the process of construction which will suffer from drillingpressure, its own gravity, torque, vibration and other kinds of load effect. Visibly, it isof great significance to study the dynamic characteristics and do dynamic designresearch of drilling rod device of the new screw pile hammers for improving thedrilling efficiency, reducing drilling cost, avoiding the drilling accidents andguaranteeing safe and reliable operation.In this thesis, the research object drilling rod device has two characteristicscompared with the traditional pile drivers: short in length and the length of drillingrod device is small relative to the diameter; external structure is complex the top ofwhich are some spline drill pipes with spline and the bottom of which is a threaded rod.This thesis uses solid elements in analysis to make sure the analysis is moreclose to actual condition considering the characteristic of the research object, whilethe traditional modal analysis most take pipe elements.This thesis takes the drilling rod device of the new screw pile hammers as theresearch object, does dynamic analysis and dynamic design on it, the main work is asfollows:1. The parametric model of drilling rod device is built based on APDL (ANSYSParametric Design Language) language which is the secondary development platformof ANSYS software. 2. The modal analysis is done on drilling rod device and the working vibration inthe process of decomposition is broken into the longitudinal vibration and horizontalvibration and torsional vibration, the influence of the main geometry size (includingthe lining thickness, length of threaded rod, the length of spline drill pipe andassembly form, etc.) on the natural frequency and inherent vibration mode is figuredout.3. The transient dynamics analysis is done on the drilling rod device during thedowntime period based on the ANSYS software to figure out the influence of themain geometry size (including the lining thickness, length of drilling rod device, etc.)on the solution of vibration.4. The dynamic design is done on the drilling rod device and a new type ofdrilling rod device is designed which has better vibration property compared with thedrilling rod device with the original size based on the solution of modal analysis&transient dynamics analysis during the downtime period.