Method for extracting first-order screw rod dispersion characteristics

An extraction method and screw rod technology, which is applied in the field of ultrasonic guided wave non-destructive testing, can solve problems such as numerical description, and achieve high fitting, good adaptability, and easy implementation

Active Publication Date: 2014-02-05
BEIJING UNIV OF TECH
View PDF2 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, complex components with first-order helical rod structures, such as steel strands and cylindrical helical compression springs, cannot directly obtain the numerical description o

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0025] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0026] 1) Establish a first-order screw rod model in the finite element simulation software, and set the material parameters (density, Young's modulus and Poisson's ratio). Select a triangular wave pulse signal with a rising edge of 0.1 μs and a falling edge of 0.2 μs as the excitation signal and load it into the center of one end of the screw rod, and set 400 receiving nodes every 1 mm at a distance of 50 mm from the loading surface in the Z direction of the screw rod generatrix. Used to acquire transient acceleration signals. Set the sampling frequency, number of sampling points and sampling time. Through simulation calculation, the transient acceleration signal x(t) of the first-order screw rod model in the radial x direction is obtained, as shown in the appendix image 3 As shown, the acceleration signals obtained on 400 receiving nodes form a row-

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a method for extracting first-order screw rod dispersion characteristics. The method includes firstly establishing a first-order screw rod module, getting M evenly spaced points as signal collection points along the direction of a Z-axis of a spiral central shaft on a generatrix of the module, calculating accelerated speed transient signals of the collection points through finite elements to form a cortege matrix X, subjecting each row vector in the X to time domain Fourier transformation, subsequently subjecting each column vector in the matrix X obtained from the above step to spatial domain Fourier transformation, transforming position information of guided wave signals to wave number information to obtain a first-order screw rod structure wave number-frequency map, drawing a first-order screw rod structure frequency-wave number dispersion curve according to characteristics of energy distribution in the wave number-frequency map, and further drawing a first-order screw rod structure frequency-phase speed dispersion curve.

Description

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Owner BEIJING UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap