CN2706755Y

CN2706755Y - Flat plate sample bending fatigue test device

Info

Publication number: CN2706755Y
Application number: CN 200320115667
Authority: CN
Inventors: 冯美斌
Original assignee: Dongfeng Motor Co Ltd
Current assignee: Dongfeng Motor Co Ltd
Priority date: 2003-10-27
Filing date: 2003-10-27
Publication date: 2005-06-29
Anticipated expiration: 2013-10-27

Abstract

The utility model relates to a dull and stereotyped sample bending fatigue test device, its characterized in that: the test device mainly comprises a vibration controller, a vibration exciter, a tuning fork resonance system and an accelerometer; the tuning fork resonance system is composed of inertia swing arms symmetrically fixed and suspended at two ends of the sample; the vibration exciter is connected with one of the swing arms through a push rod; the accelerometer is fixed on the other swing arm and is respectively connected with the voltmeter and the vibration controller through the charge amplifier by a circuit. The device not only solves the problem of carrying out the bending fatigue test of the flat plate sample under the symmetrical cyclic load, but also has the advantages of high loading frequency, convenient load adjustment, visual display, high precision of the bending moment in a wide range, wide sample adaptability and the like.

Description

A kind of dull and stereotyped sample repeated bend test device

Technical field: the utility model belongs to the material test technical scope, particularly a kind of dull and stereotyped sample repeated bend test device.

Background technology: the repeated bend test of dull and stereotyped sample adopts the load mode of three-point bending or four-point bending usually, on HF fatigue testing machine, carry out, its shortcoming is to apply unidirectional fluctuating load, can not satisfy the material under the cyclic bending load-up condition and the test request of plate part.Though can apply reciprocal load, there is following shortcoming in it to existing dull and stereotyped sample fatigue bending machine (as the PWO type mechanical testing machine of German Carl Schenck AG production): moment of flexure is regulated difficulty; Moment of flexure can not show; The sample clamping easily produces additional bending moment; The load precision is low, and error is greater than 5%; Loading frequency is low, about 20～30 hertz; The designs fix of sample.Therefore, existing dull and stereotyped sample repeated bend test device does not satisfy actual needs.

Summary of the invention: the utility model regulate difficulty for the moment of flexure that solves existing dull and stereotyped sample repeated bend test device and exist and can not show, the sample clamping easily produces problems such as additional bending moment, the load precision is low, loading frequency is low, proposes a kind of dull and stereotyped sample repeated bend test device.

This flat board sample repeated bend test device, it is characterized in that: described test unit mainly is made up of vibrating controller, vibrator, tuning fork resonator system, accelerometer; Described tuning fork resonator system is to be made of the inertia swing arm that fixedly is suspended on the sample two ends symmetrically; Described vibrator links to each other with a swing arm wherein by push rod; Described accelerometer is fixed in another swing arm, and is connected with voltage table, vibrating controller respectively through charge amplifier by circuit.

The utility model has not only solved under the symmetrical cycle load and has carried out the difficult problem of dull and stereotyped sample repeated bend test, and have that loading frequency height (reaching as high as more than 100 hertz), load are easy to adjust, intuitive display, moment of flexure can keep higher precision (error is less than 2%) in very wide scope and the advantages such as wide adaptability of sample.

Description of drawings: Fig. 1 is the theory diagram of the dull and stereotyped sample repeated bend test of the utility model device.

Embodiment: as shown in Figure 1, test unit mainly is made up of parts such as vibrating controller 10, vibrator 8, tuning fork resonator system, accelerometers 2; The tuning fork resonator system is to be made of the inertia swing arm 1,21 that is fixed on sample 3 two ends symmetrically, inertia swing arm 1,21 is fixed on symmetrically the two ends of dull and stereotyped sample 3 with fastening bolt 5 and gland 6, with wire rope 4 inertia swing arm 1,21 is hung then, and make dull and stereotyped sample 3 keep horizontality; Vibrator 8 links to each other with inertia swing arm 1 by push rod 7; Accelerometer 2 utilizes magnetic support to be fixed on the appropriate location of inertia swing arm 21, and is connected with digital voltmeter 11, vibrating controller 10 respectively through charge amplifier 12 by circuit.Under less load amplitude, regulate the frequency of the command signal in the vibrating controller 10 after the opening power, make system be in resonance state; Progressively increase the amplitude of the command signal in the vibrating controller 10, command signal is spread out of by power amplifier 9, and the moment of flexure reading in the digital voltmeter 11 is equated with predetermined value, and dull and stereotyped sample 3 just moves under predetermined symmetrical cycle load, and counting begins simultaneously.Test finishes automatically when one of following situation occurring: the sample Cracking Failure; Test run is to the period of appointment.

When electric activator 8 during with certain frequency and amplitude excitation system, the sinusoidal wave moment of flexure of the symmetry that inertial force produced of swing arm 1 just is applied on the sample 3, and this frequency equals the resonance frequency of tuning fork system.The amplitude M of moment of flexure is had by accelerometer 2 tolerance that are placed in another swing arm 21:

M＝Ja/l

J is swing arm 1,21 moment of inertia around centre of oscillation axis in the formula, and a is an accekeration, and l is the distance of accelerometer to centre of oscillation axis.

The charge signal that accelerometer 2 is produced is used to show moment of flexure numerical value and delivers to electronic control part or vibrating controller 10 participation closed-loop controls as the response of system after charge amplifier 12 amplifies and converts the voltage signal of standard quantification to.The adjusting of load, counting, the detection of sample cracking and the functions such as protection of shutdown and load amplitude provide by electronic control part.

The utility model has not only solved a difficult problem of carrying out dull and stereotyped sample repeated bend test under the symmetrical cycle load, and have that loading frequency height, load are easy to adjust, intuitive display, moment of flexure can keep the higher precision and the advantages such as wide adaptability of sample in very wide scope, its loading frequency reaches as high as more than 100 hertz, and moment of flexure in very wide scope retainable trueness error less than 2%.

Claims

1, a kind of dull and stereotyped sample repeated bend test device, it is characterized in that: described test unit mainly is made up of vibrating controller, vibrator, tuning fork resonator system, accelerometer; Described tuning fork resonator system is to be made of the inertia swing arm that fixedly is suspended on the sample two ends symmetrically; Described vibrator links to each other with a swing arm wherein by push rod; Described accelerometer is fixed in another swing arm, and is connected with voltage table, vibrating controller respectively through charge amplifier by circuit.

2, require 1 described dull and stereotyped sample repeated bend test device as patent right, it is characterized in that: described vibrator is an electric activator.