Unlock instant, AI-driven research and patent intelligence for your innovation.

Measuring method in normal stress and shear stress test of compression spring

A stress measurement and compression spring technology, applied in force/torque/work measuring instruments, measuring devices, measuring force components, etc., can solve the problems of not considering the change of the helix angle, the error of the calculation result, etc.

Inactive Publication Date: 2005-09-14
BEIJING JIAOTONG UNIV
View PDF0 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, since the calculation formula is completely based on the theory of material mechanics, the calculation process does not consider the increase of the spring outer diameter during the compression process, the change of the helix angle caused by the decrease of the pitch, and other factors affecting the stress distribution. possible impact
Therefore, there is a certain error in the calculation result

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Measuring method in normal stress and shear stress test of compression spring
  • Measuring method in normal stress and shear stress test of compression spring
  • Measuring method in normal stress and shear stress test of compression spring

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0013] The present invention will be further described with accompanying drawing as embodiment:

[0014] as attached figure 2 As shown, under the axial pressure P of the coil spring, the torque M on the cross section of the spring wire 扭 and bending moment M 弯 They are:

[0015]

[0016]

[0017] where D and α are the spring diameter and helix angle, respectively. The shear stress τ caused by its torque and bending moment 理 and the normal stress σ 理 They are:

[0018]

[0019]

[0020] where W t , W and d are the torsional section coefficient, the bending section coefficient and the wire diameter of the spring, respectively. Therefore, for a helical spring with a determined size and structure, under different compression loads P, the theoretical values ​​of shear stress and normal stress can be calculated using formula (1).

[0021] In order to make practical measurements of shear and normal stresses caused by torque and bending moments of cylindrical heli...

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 compression spring direct and shear stress experimental measuring method, the loaded test piece of which is circular helical spring.The experiment comprises two steps: first, electric resistance foil gages from first to forth switching in Wheatstone bridge arm in turn; second, transposing bridge arm order of the second and third electric resistance foil gages, then conducting compression experiment in universal electronic testing machine and recording load of different time and strain of different time by strain meter; finally, inputting them into computer and unloading when amounting to the maximum load.

Description

technical field [0001] The invention relates to a method for measuring the stress of a compressed spring, in particular to an experimental method for measuring the normal stress and shear stress of a compressed spring. Background technique [0002] Spring is a widely used mechanical part. There are many kinds of springs. In addition to common cylindrical coil springs, it also includes leaf springs, leaf springs, disc springs and so on. It uses the elasticity and structural characteristics of the material to produce deformation during work, transforming mechanical energy into deformation energy, and vice versa, transforming deformation energy into mechanical energy or kinetic energy. During the use of the spring, it mainly plays the role of bearing pressure and reducing vibration. For ordinary cylindrical coil springs, due to their helical structure, under the action of axial load, normal stress and tangential stress should be generated at the same time. [0003] At present,...

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
IPC IPC(8): G01L5/00G01L5/16G01M13/00
Inventor 王正道康爱健
Owner BEIJING JIAOTONG UNIV