Drill Bit Tooth Mechanics Calculation with Dynamic Rock Strength
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Solution Overview
Problem
Current mechanical models for drill bit tooth interactions with rocks primarily focus on single failure modes and static strength, neglecting dynamic strength and mixed crushing modes, which limits the accuracy in calculating the forces involved in rock crushing during deep drilling.
Innovation Solution
A mechanics calculation method that considers rock dynamic strength and mixed crushing modes by determining the type and geometry of the drill bit tooth, calculating horizontal and vertical penetration forces, and resultant forces using specific formulas involving dynamic rock strengths and friction angles, with the aid of a processor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If numerical simulation methods (finite element method, finite difference method, discrete element method) are used to calculate drill bit tooth mechanics, then the calculation comprehensively considers complex stress processes including tensile failure, compression failure and shear failure, but the computational speed is slower compared to analytical solutions
Solution Approach 1:
The patent segments the complex rock crushing process into distinct failure modes (tensile failure, compression failure, shear failure) and applies specific analytical formulas for each mode. This segmentation allows the use of simplified analytical solutions for each failure type while maintaining comprehensive coverage of the complex stress process, thus achieving both accuracy and computational efficiency.
Solution Approach 2:
The patent introduces dynamic strength parameters (dynamic tensile strength, dynamic compressive strength, dynamic shear strength) that change with loading rate, and uses these parameters in analytical formulas to account for dynamic loading effects. This parameter transformation allows analytical solutions to capture dynamic behavior without requiring full numerical simulation, improving computational speed while maintaining accuracy.
2Productivity
If classical analytical models based on single failure mode and static strength are used, then the calculation is simple and fast, but the real dynamic force characteristics of crushing rocks cannot be accurately considered
Solution Approach 1:
The patent transforms static strength parameters into dynamic strength parameters by introducing loading rate effects. The dynamic tensile strength, dynamic compressive strength, and dynamic shear strength are explicitly defined as functions of loading rate, allowing the analytical model to capture dynamic force characteristics while maintaining computational simplicity and speed.
Solution Approach 2:
The patent creates a composite analytical model that combines multiple failure mode formulations (tensile, compression, shear) with dynamic strength parameters. This composite approach integrates the advantages of different analytical models and incorporates dynamic effects, achieving accurate dynamic force characterization without sacrificing calculation speed.
3Device complexity
If existing mechanical models consider only single crushing strength mode and static or quasi-static strength mechanics theory, then the model complexity is reduced, but the comprehensive consideration of cutting speed, dynamic strength and mixed crushing mode is insufficient
Solution Approach 1:
The patent develops a universal analytical model that can handle multiple failure modes (tensile, compression, shear) and dynamic loading conditions through a unified framework. The model uses general formulas with dynamic strength parameters that adapt to different rock types and loading rates, making it versatile for various drilling conditions while maintaining relatively simple model structure.
Data Source
AI summary
The invention discloses a mechanics calculation method of drill bit tooth considering rock dynamic strength and mixed crushing mode, including: Step S1: selecting a target drill bit tooth and a target rock, and determining a type of target drill bit tooth, a geometry of the target drill bit tooth, a rock type and rock parameters of the target rock; Step S2: calculating a horizontal cutting force of the target drill bit tooth according to a horizontal cutting mechanics calculation method of drill bit tooth; Step S3: calculating a vertical penetration force of the target drill bit tooth according to a vertical penetration mechanics calculation method of drill bit tooth; Step S4: calculating a resultant force experienced by the target drill bit tooth according to a resultant force calculation method of drill bit tooth. The invention provides a calculation method for accurately obtaining drill bit tooth mechanics under different working conditions.