A Robust Optimization Method on the Transmission System of the Cutting Unit of Shearer

2020 ◽  
Author(s):  
Hongbin Gao ◽  
Junjun Chen
Keyword(s):  
Robust Optimization ◽  
Design Method ◽  
Harmonic Balance Method ◽  
Optimization Method ◽  
Transmission System ◽  
Manufacturing Cost ◽  
Internal Excitation ◽  
Tooth Width ◽  
Solution Methods ◽  
Cutting Unit

Abstract The transmission system of the cutting unit of shearer is divided into three basic components: planetary reduction form, one gear on one shaft form and a double gears on one shaft. The dynamic differential equations of three basic components are established respectively, and the volume functions of each structure are obtained. The characteristics of the internal excitation of the transmission system are analyzed, and the solution methods of the motion parameters of each component are obtained based on the harmonic balance method. Taking the parameters such as tooth number, modulus and tooth width as optimized variables, and a robust optimization method with the minimum value of multi-parameter evaluation function weighted linearly by dimensionless volume and vibration for the transmission system of the cutting unit of shearer is presented. Taking a certain type of shearer as an example, the transmission system of the cutting unit is optimized by using the presented method. After the design, the size is reduced by 5.4%, the maximum torsional acceleration of the drum is reduced by 17.8%, and the maximum torsional acceleration of the first gear is reduced by 9.6%. The results show that the design method can reduce the manufacturing cost of shearer and reduce the failure rate of the cutting unit.

Intelligent Optimization Design of the Cutting Unit’s Transmission System of a Shearer Based on Robustness

2021 ◽  
pp. 2158009
Author(s):  
Hongbin Gao ◽  
Junjun Chen
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Harmonic Balance Method ◽  
Optimization Method ◽  
Transmission System ◽  
Gear Transmission ◽  
Manufacturing Cost ◽  
Tooth Width ◽  
Gear Transmission System ◽  
Cutting Unit

To improve the robustness of the shearer cutting part and reduce the manufacturing cost, in this study, the gear transmission system of a shearer’s cutting unit can be divided into three basic components: single-gear-on-one-shaft form, the planetary reduction form, and double-gears-on-one-shaft form. The dynamic differential equations of each structure are established in this study, and the volume functions of the three basic components are obtained. The characteristics of the internal excitation of the gear transmission system are analyzed, and a scheme for solving the motion parameters of each component is formulated based on the harmonic balance method. Based on the parameters, such as tooth width, tooth number, and modulus, as optimized variables, a robust optimization method minimizing the multi-parameter evaluation function, which is weighted linearly by dimensionless vibration and volume of the gear transmission system, is presented. The gear transmission system of a sample shearer’s cutting unit is optimized using the proposed method. The results show that the transmission system’s size decreases by 5.4%, the drum’s maximum torsional acceleration decreases by 17.8%, and the first gear’s maximum torsional acceleration decreases by 9.6%. Thus, we conclude that the optimum design method decreases a shearer’s manufacturing cost and decreases the cutting unit’s failure rate.

scholarly journals Lightweight and maintainable rotary-wing UAV frame from configurable design to detailed design

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110349
Author(s):  
Huiqiang Guo ◽  
Mingzhe Li ◽  
Pengfei Sun ◽  
Changfeng Zhao ◽  
Wenjie Zuo ◽  
...  
Keyword(s):  
Design Method ◽  
Geometric Model ◽  
Optimization Method ◽  
Frame Structure ◽  
Manufacturing Cost ◽  
Detailed Design ◽  
High Manufacturing Cost ◽  
The Military ◽  
Rotary Wing ◽  
Novel Design

Rotary-wing unmanned aerial vehicles (UAVs) are widespread in both the military and civilian applications. However, there are still some problems for the UAV design such as the long design period, high manufacturing cost, and difficulty in maintenance. Therefore, this paper proposes a novel design method to obtain a lightweight and maintainable UAV frame from configurable design to detailed design. First, configurable design is implemented to determine the initial design domain of the UAV frame. Second, topology optimization method based on inertia relief theory is used to transform the initial geometric model into the UAV frame structure. Third, process design is considered to improve the manufacturability and maintainability of the UAV frame. Finally, dynamic drop test is used to validate the crashworthiness of the UAV frame. Therefore, a lightweight UAV frame structure composed of thin-walled parts can be obtained and the design period can be greatly reduced via the proposed method.

A robust structural design method using the Kriging model to define the probability of design success

2010 ◽  
Vol 224 (2) ◽  
pp. 379-388 ◽  
Author(s):  
K-H Lee
Keyword(s):  
Robust Optimization ◽  
Design Method ◽  
Mathematical Problem ◽  
Kriging Model ◽  
Optimization Method ◽  
Design Problems ◽  
Kriging Metamodel ◽  
Mean And Variance ◽  
Kriging Approximation ◽  
Design Requirements

In this study, a robust optimization method is proposed by introducing the Kriging approximation model and defining the probability of design-success. A key problem in robust optimization is that the mean and the variation of a response cannot be calculated easily. This research presents an implementation of the approximate statistical moment method based on the Kriging metamodel. Furthermore, the statistics using the second-order statistical approximation method are adopted to avoid the local robust optimum. Thus, the probability of design-success, which is defined as the probability of satisfying the imposed design requirements, is represented as a function of approximate mean and variance. The formulation for the robust optimization can be defined as the probability of design-success of each response. The mathematical problem and the design problems of a two-bar structure and microgyroscope are investigated for the validation of the proposed method.

Frequency Reliability Robust Optimization for Rotor System

2012 ◽  
Vol 479-481 ◽  
pp. 1023-1026
Author(s):  
Chang Qing Su ◽  
Le Xin Li
Keyword(s):  
Robust Optimization ◽  
Robust Design ◽  
Design Theory ◽  
Optimization Design ◽  
Design Method ◽  
Optimization Method ◽  
Rotor System ◽  
Reliability Design ◽  
Reliability Sensitivity ◽  
Reliability Robust Design

The material properties and geometry of rotor system are random parameters because of the manufacturing environment, manufacturing and installation errors and other factors. Based on the reliability design theory, the reliability sensitivity technique and the robust design method, the frequency reliability robust optimization method of rotor system is extensively discussed. The frequency reliability sensitivity is added to the reliability-based optimization design model of rotor system. The frequency reliability robust design is described as a multi-objection optimization. The method presented provided the theoretic basis for the reliability robust design of the rotor system. A numerical example demonstrated that the proposed method is effective.

scholarly journals Surrogate-Based Optimization of Horizontal Axis Hydrokinetic Turbine Rotor Blades

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4045
Author(s):  
David Menéndez Arán ◽  
Ángel Menéndez
Keyword(s):  
Turbine Blade ◽  
Design Method ◽  
Optimization Method ◽  
Turbine Rotor ◽  
Computational Effort ◽  
Rotor Blades ◽  
Linear Functions ◽  
Cavitation Inception ◽  
Hydrokinetic Turbine ◽  
Blade Geometry

A design method was developed for automated, systematic design of hydrokinetic turbine rotor blades. The method coupled a Computational Fluid Dynamics (CFD) solver to estimate the power output of a given turbine with a surrogate-based constrained optimization method. This allowed the characterization of the design space while minimizing the number of analyzed blade geometries and the associated computational effort. An initial blade geometry developed using a lifting line optimization method was selected as the base geometry to generate a turbine blade family by multiplying a series of geometric parameters with corresponding linear functions. A performance database was constructed for the turbine blade family with the CFD solver and used to build the surrogate function. The linear functions were then incorporated into a constrained nonlinear optimization algorithm to solve for the blade geometry with the highest efficiency. A constraint on the minimum pressure on the blade could be set to prevent cavitation inception.

A Mathematical Principle and Application on Design of Planar Six-Bar Mechanism with unto Three-Ordered Intermission at Limit Position(s)

2010 ◽  
Vol 37-38 ◽  
pp. 9-13
Author(s):  
Hong Xin Wang ◽  
Ning Dai
Keyword(s):  
Design Method ◽  
Optimization Method ◽  
Basic Function ◽  
Mathematical Principle ◽  
Transmission Characteristics ◽  
Basic Functions ◽  
Combined Mechanism ◽  
Limit Position ◽  
Derivatives Of ◽  
Better Than

A non-iterative design method about high order intermittent mechanisms is presented. The mathematical principle is that a compound function produced by two basic functions, and then one to three order derivatives of the compound function are all zeroes when one order derivative of each basic function is zero at the same moment. The design method is that a combined mechanism is constructed by six bars; the displacement functions of the front four-bar and back four-bar mechanisms are separately built, let one order derivatives of two displacement functions separately be zero at the same moment, and then get geometrical relationships and solution on the intermittent mechanism. A design example shows that this method is simpler and transmission characteristics are better than optimization method.

scholarly journals Optimal design of high efficiency double helical gear based on dynamics model

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Fengxia Lu ◽  
Xuechen Cao ◽  
Weiping Liu
Keyword(s):  
Dynamic Model ◽  
High Efficiency ◽  
Bending Strength ◽  
Sliding Friction ◽  
Elastohydrodynamic Lubrication ◽  
Optimization Method ◽  
Transmission Efficiency ◽  
Helical Gear ◽  
Transmission System ◽  
Vibration Displacement

AbstractA 16-degree-of-freedom dynamic model for the load contact analysis of a double helical gear considering sliding friction is established. The dynamic equation is solved by the Runge–Kutta method to obtain the vibration displacement. The method combines the friction coefficient model based on the elastohydrodynamic lubrication theory with the dynamic model, which provides a theoretical basis for the calculation of the power loss of the transmission system. Moreover, the sensitivity analysis of the parameters that affect the transmission efficiency is carried out, and an optimization method of meshing efficiency is proposed without reducing the bending strength of the gears. This method can directly guide the design of the double helical gear transmission system.

Comprehensive Design Method for Open or Ducted Propellers for Underwater Vehicles

2021 ◽  
Author(s):  
Spyros A. Kinnas ◽  
Kyungjung Cha ◽  
Seungnam Kim
Keyword(s):  
Design Method ◽  
A Priori ◽  
Optimization Method ◽  
Underwater Vehicles ◽  
Current Approach ◽  
Lattice Method ◽  
B Spline ◽  
Effective Wake ◽  
Propeller Thrust ◽  
Ducted Propellers

A comprehensive method which determines the most efficient propeller blade shapes for a given axisymmetric hull to travel at a desired speed, is presented. A nonlinear optimization method is used to design the blade, the shape of which is defined by a 3-D B-spline polygon, with the coordinates of the B-spline control points being the parameters to be optimized for maximum propeller efficiency, for given effective wake and propeller thrust. The performance of the propeller within the optimization scheme is assessed by a vortex-lattice method (VLM). To account fully for the hull/propeller interaction, the effective wake to the propeller and the hull resistance are determined by analyzing the designed propeller geometry by the VLM, coupled with a Reynolds-Averaged Navier-Stokes (RANS) solver. The optimization method re-designs the optimum blade with the updated effective wake and propeller thrust (taken to be equal to the updated hull resistance), and the procedure continues until convergence of the propeller performance. The current approach does not require knowledge of the wake fraction or the thrust deduction factor, both of which must be estimated a priori in traditional propeller design. The method is applied for a given hull to travel at a desired speed, and the optimum blades are designed for various combinations of propeller diameter and RPM, in the case of open and ducted propellers with provided duct shapes. The effects of the propeller diameter and RPM on the designed propeller thrust, torque, propeller efficiency, and required power are presented and compared with each other in the case of open and ducted propellers. The present approach is shown to provide guidance on the design of propulsors for underwater vehicles, and is applicable to the design of propulsors for surface ships.

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