CN102650578A - Testing method for normal temperature and high temperature stress relaxation of flat spring - Google Patents

Testing method for normal temperature and high temperature stress relaxation of flat spring Download PDF

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Publication number
CN102650578A
CN102650578A CN2012101239379A CN201210123937A CN102650578A CN 102650578 A CN102650578 A CN 102650578A CN 2012101239379 A CN2012101239379 A CN 2012101239379A CN 201210123937 A CN201210123937 A CN 201210123937A CN 102650578 A CN102650578 A CN 102650578A
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sample
measured
hole
upper plate
base
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CN102650578B (en
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赵丽
张卫方
李晓刚
刘升旺
唐庆云
杨明远
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Beihang University
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Beihang University
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Abstract

The invention provides a testing method for normal temperature and high temperature stress relaxation of a flat spring. Firstly, a to-be-tested spring sample is prepared, the prepared to-be-tested spring sample is an equal stress sample and has a symmetrical-shaped flat structure; secondly, installation and test preparation of testing equipment are performed, the testing equipment is provided with a base, lateral plates are fixed on the front and the rear sides of the base, the two ends of the to-be-tested spring sample are respectively placed on the lateral plates, the base and an upper plate are fixed together through a limiter, a pressure sensor is mounted on the upper plate, and a pressure head mounted at the lower end of the pressure sensor exerts pressure force onto the sample; then a spring stress relaxation test is performed, and the stress values at different time can be collected; and finally, the condition of stress relaxation loss of the material of the sample is determined. Through the method provided by the invention, the bending deflection of the sample, which is difficult to measure, is converted into electrical signals easy to measure, the work efficiency is improved, the method is simple, and the testing data is accurate.

Description

The method of testing of a kind of springs normal temperature and high-temperature stress relaxation
Technical field
The invention belongs to normal temperature and high temperature springs stress relaxation technical field of measurement and test, be specifically related to the method for testing of a kind of springs normal temperature and high-temperature stress relaxation.
Background technology
The stress relaxation size is as one of standard of investigating material property, and the relaxation test of current country variant counter stress does not have unified standard, and sample is also different with proving installation.Therefore test result is widely different, can't unify comparison.The common method of springs stress relaxation test at present is variable cross section cantilever method and mandrel method.Wherein cantilever method is with a variable cross section sample, produces a constant fiber strain when crooked.Make sample crooked with bolt, be fixed in a height to " free end ", this height is corresponding to desired stress level.The method need be confirmed stress and Deflection Relationship.The mandrel method is to wrap in the parallel reed sample of opposite side on the mandrel, selects different mandrels can produce desired primary stress.Be clamped in sample on the mandrel, be put into different time in the high temperature that has been provided with, remove sample from mandrel then, measure the curvature that is produced with optical comparator and special fixtures.
The test fixture of above-mentioned shock mount stress relaxation sample, great majority are to design voluntarily.The method that hemisphere loads and piston loads is adopted in the ASTM standard recommendation.Very little for the required applied stress of thin slice sample, it is higher to measure the applied stress sensor accuracy, and as adopting the piston load mode of ASTM standard recommendation, then the error that causes of effect such as the friction force of loading system own possibly surpass and tests required measuring accuracy.General employing bolt adds load measuring method through the bolt loading at present, will be bolted on the base then.This method automaticity is lower, and error is relatively large, and can not realize being with temperature measurement, because the limitation of device itself need be fixed through other stationary installations.Increase labor capacity to a great extent, increased the complicacy and the instability of device.
Summary of the invention
The automaticity that the test of springs normal temperature and high-temperature stress relaxation exists in the prior art is lower in order to solve, error is big in the present invention, measuring complex and problem of unstable, and a kind of springs normal temperature and high-temperature stress relaxation method of testing are provided.
The present invention proposes the method for testing of a kind of springs normal temperature and high-temperature stress relaxation, realizes through following steps:
Step 1, the preparation of spring sample to be measured and processing:
Step 1.1: blanking, selected stress relaxation test material;
Step 1.2: the material warp is cut into the equal stress sample; Described equal stress sample is the schistose texture with symmetric shape, and an end of sample has the hole;
Step 1.3:, reach the mechanical state of regulation with the Ageing Treatment that spring sample to be measured is stipulated.
Step 2, the installation of testing apparatus and test are prepared.
Step 2.1: will set the crooked primary stress of reed and bring the initial deflection computing formula into, and confirm the vertical drop of limiter and front side board.
Step 2.2: installation testing equipment; Described testing apparatus comprises: base, limiter, upper plate, pressure transducer, pressure head, front side board and back side panel; In when assembling, at first, front side board and back side panel are separately fixed at the front side and the rear side of base, said front side board, back side panel and base, being centered close on the same vertical horizontal line of three's downside; Secondly, through in the center counterbore that is bolted to the front side board upside, the other end of spring sample to be measured is placed in the groove in back side panel upside centre position with an end of spring sample to be measured perforate; Then, pressure head is fixed on the lower end of pressure transducer, the upper end of pressure transducer is fixed on the central through hole of upper plate, pressure transducer is positioned at the downside of upper plate; At last, assembling limiter, left counterbore that base has and right counterbore; The left through hole and the right through hole of the vertical corresponding upper plate of difference; The left through hole of described upper plate and right through hole are with respect to the central through hole left-right symmetric of upper plate, and base is vertical corresponding with the center of upper plate, the left limiter of assembling between the left counterbore of base and upper plate left side through hole; The right limiter of assembling between the right through hole of the right counterbore of base and upper plate; The two ends band external thread of described limiter, lower end are fixed in the left counterbore or right counterbore of base, and the upper end is through being bolted on upper plate left side through hole or the right through hole.
Step 2.3: the sensor lead that will connect pressure transducer links to each other with external data presentation instrument; And the power lead and the power supply of data presentation instrument joined, be under zero test mode at described measuring equipment the data Displaying Meter is returned to zero and range calibration.
Step 2.4: tighten the nut of upper plate and arranged on left and right sides stationary restraint, guarantee as far as possible in the rundown process that spring sample to be measured both sides are stressed evenly, after the data stabilization of pending data Displaying Meter, read primary stress;
Step 3; Carry out the spring stress relaxation test and gather the stress value of different time, specifically: the proving installation that will have spring sample to be measured is placed in the high-temperature test chamber energized; Regulate the temperature of chamber, the bending stress value of sheet sample under the record different time;
Step 4 reaches the regulation test period, reads the instrument displayed value of termination test during the time; From chamber, taking out testing apparatus cools off; With the testing apparatus unloading, take out spring sample to be measured after the cooling, under free state, parked one hour; With the height of the recovery after the flexural deformation of strain-ga(u)ge measurement spring sample to be measured, and then the stress relaxation damaed cordition of definite this reed material.
The advantage and the good effect of the inventive method are:
(1) method of definite stress at present commonly used and Deflection Relationship is when applying various amount of deflection level to sample; Obtain a strain-sag curve with strainmeter; Confirm the stress-strain behavior of material to utilize this characteristic to set up sag with axial test, produce desired stress application.The present invention need not confirm stress and Deflection Relationship, the sample sag that is difficult for measuring is converted into the electric signal that is prone to measurement.In addition; Measuring method at present commonly used is the temperature that sample is put into setting; Place certain hour, remove sample from its anchor clamps then, measure the permanent strain that produces with optical comparator; Be converted into loss stress to permanent strain then, and the inventive method need not be converted into loss stress with permanent strain.Therefore, compare existing method, the present invention's operation is simpler.
(2) the inventive method is monitored the variation of compression stress in real time through pressure transducer and external data presentation instrument; Need not sample be taken out test in the process of the test; Need not change sample, the factor that influences data fluctuations is less, has guaranteed accuracy, repeatability and the repeatability of test data.
(3) pressure transducer of the inventive method employing and the sensor lead of output all are applicable to hot conditions, so the present invention can carry out the test of springs stress relaxation.
(4) the inventive method need not averaged to the sample measurement several times, thereby has improved work efficiency, has avoided the error of bringing because of the circulation survey record.
(5) sample that the present invention adopted is the schistose texture with symmetric shape, has guaranteed not produce in the sample BENDING PROCESS lateral thrust; The specimen size design avoids producing because clamping loads the influence of the termination effect belt that brings; Sample is a symmetrical structure, and is stressed in the centre position, and the symmetric position in centre position is also stressed identical relatively, is easy to test and analysis.
Description of drawings
Fig. 1 is the front elevation of the general assembly drawing of testing apparatus of the present invention;
Fig. 2 is the rear view of the general assembly drawing of testing apparatus of the present invention;
Fig. 3 is the synoptic diagram of upper plate in the testing apparatus of the present invention: a is a vertical view, and b is A-A directional profile figure;
Fig. 4 is the synoptic diagram of base in the testing apparatus of the present invention: a is a vertical view, and b is a B-B direction cut-open view, and c is front view or rear view;
Fig. 5 is the structural representation of front side board in the testing apparatus of the present invention: a is a front view, and b is a vertical view;
Fig. 6 is the structural representation of back side panel in the testing apparatus of the present invention: a is a front view, and b is a vertical view;
Fig. 7 is the structural representation of limiter in the testing apparatus of the present invention;
Fig. 8 is the structural representation of pressure transducer in the testing apparatus of the present invention;
Fig. 9 is the structural representation of pressure head in the testing apparatus of the present invention: a is a front view, and b is a side view;
Figure 10 is the structural representation of cushion block in the testing apparatus of the present invention;
Figure 11 is the specimen shape figure of the present invention's springs to be measured;
Figure 12 is the flow chart of steps of method of testing of the present invention.
Embodiment
The detailed explanation of the present invention being carried out below in conjunction with accompanying drawing.
Test mode provided by the invention is based on following a kind of testing apparatus, and is as shown in figures 1 and 3, and this testing apparatus mainly comprises following several module: base 1, limiter 2, upper plate 3, pressure transducer 4, pressure head 5, front side board 6 and back side panel 7.
As illustrated in fig. 1 and 2, upper plate 3 be flat on base 1 directly over, base 1 is corresponding with the center of upper plate 3.Two limiters 2 were fixed together about base 1 passed through with upper plate 3.On the center of a side of the relative base 1 of upper plate 3, be fixed with pressure transducer 4, the other end of pressure transducer 4 is fixed with pressure head 5.Pressure transducer 4 is connected with external data presentation instrument through sensor lead 8, gives external data presentation instrument with the pressure transmission of the pressure head of measuring 5.Be fixed with front side board 6 and back side panel 7 respectively in the both sides, front and back of base 1, the two ends of springs to be measured are placed on respectively on front side board 6 and the back side panel 7.In test time, after springs to be measured placed, pressure head 5 was positioned at the position, middle of springs to be measured.
Shown in a and b of Fig. 3, the center on the upper plate 3 has through hole 32, is used for fixing pressure transducer 4, respectively has a through hole 31 in central through hole 32 symmetrical positions, is used to assemble limiter 2.On the transverse horizontal line that was centered close to central through hole 10 of left and right two through holes 31 shown in a of Fig. 3.
Shown in a and b of Fig. 4, the upside of base 1, the position of the left and right through hole 31 of vertical corresponding upper plate 3 respectively has two counterbores 11, is used for an end of stationary restraint 2 is fixed on lower plate 1, guarantees that lower plate 1 is smooth.Shown in the c of Fig. 4, the front and back side of base 1 respectively has two holes 12, is used for fixing front side board 6 and back side panel 7.
Upper plate 3 all is dull and stereotyped with base 1, by chrome-plated material, stainless steel or other high temperature resistant, resistant material manufacturings, carries out high polish, has higher surface smoothness, the depth of parallelism and rigidity.
Shown in a of Fig. 5, have two holes 12 that open corresponding base 1 front side, position of 61, two through holes 61 of two through holes in the side of front side board 6, can front side board 6 be fixed on the base 1 through screw.Shown in the b of Fig. 5, have counterbore 62 in the center of the upside of front side board 6, be used for fixing an end of springs to be measured.In order to make springs to be measured more firm at the trial, near a week of counterbore 62, also evenly have 4 counterbores 63, be used for fixing springs to be measured.When fixing springs to be measured, be placed on spring perforate one end to be measured with a cushion block III, through bolt cushion block III, springs to be measured and front side board 6 are fixed together.The structure of cushion block III is shown in figure 10.
Shown in a among Fig. 6, the side of back side panel 7 has two holes 12 that corresponding base 1 rear side in position of 71, two through holes 71 of two through holes is opened, and can back side panel 7 be fixed on the base 1 through screw.Shown in b among Fig. 6; The upside of back side panel 7 has groove 72, is used to place the other end of springs to be measured, and the width of groove 72 is slightly larger than the width of springs to be measured end; Springs to be measured can be placed in the groove 72, avoids sample generation move left and right in the test.The bottom surface of the groove of being opened on the back side panel 7 72 and the upper side of front side board 6 are on the same surface level.
As shown in Figure 7; The two ends band external thread of limiter 2; Pass the through hole 31 on upper plate 3 left sides or the right at a last end, and limiter 2 is fixing with upper plate 3 with nut, limiter 2 under an end be fixed in the counterbore 11 of through hole 31 on vertical corresponding upper plate 3 left sides or the right on the lower plate 1.Limiter 2 adopts stainless steel material to process, and its height decides according to the deflection deformation rate of sheet spring, is compressed to the height value of regulation in order to guarantee sample, produces constant deformation, and its height allowable tolerance is 0.02mm.
As shown in Figure 8, the two ends band external thread of pressure transducer 4, pressure transducer 4 pass the central through hole 11 of upper plate 3 at a last end; And be fixed on the upper plate 3 through nut; Under an end pressure head 5 has been installed, be used to avoid the bolt springs direct and to be measured of pressure transducer 4 to contact, cause stress distribution uneven; And avoid springs hot mastication reblocking pressure transducer 4 to be measured, the problem that 4 serviceable lifes of build-up of pressure sensor and test accuracy descend.The head of the end that pressure transducer 4 is connected with pressure head 5 is a polished rod, and it is for fear of following situation that one section polished rod is set: thereby owing to use repeatedly and cause thread abrasion to cause the gap that contacts between pressure transducer 4 and the pressure head 5, and then influence measuring accuracy.The specification of the pressure transducer of being selected for use in the testing apparatus of the present invention is kz β k-1, and accuracy grade is 0.001, and output sensitivity is 2.248mV/V, and temperature range is 0 ℃~150 ℃, and range is 980N.Pressure transducer 4 is anodal through the outer power supply source input end transparent thread of data presentation instrument that sensor lead 8 connects, and the black negative utmost point, instrument input end yellow line are anodal, and white line is a negative pole.Pressure transducer 4 measuring accuracy in the testing apparatus of the present invention reach per mille, and temperature is floated little and can at high temperature be kept good precision.
As shown in Figure 9, pressure head 5 is fixed on the pressure transducer 4 through internal thread.Corresponding to the polished rod that pressure transducer 4 one ends are provided with, there is one section smooth section too in the internal thread in the pressure head 5, shown in a of Fig. 9.The polished rod that pressure transducer one end is set in the embodiment of the invention is 3-5mm, and is same, and the position bottom internal thread is in the corresponding pressure head 5 is provided with the smooth section of 3-5mm.In addition; To tested object is springs, and pressure head 5 is that line contacts with spring, makes that the stressed position of tested springs is a line; And the width at the position that pressure head 5 contacts with tested springs is greater than the width of tested springs; Avoid spring because test causes problems such as crimping, make that test is more accurate, also practiced thrift test specimen.
For making present device have versatility, designed three kinds of cushion block I, II and III, shown in figure 10, three kinds of cushion blocks are a rectangle all, the center has through hole, on the circumferencial direction of central through hole, also evenly has four through holes.Cushion block I is used for the auxiliary desired load that is provided with; The diameter of central through hole that cushion block I is set is greater than limiter 2 upper end diameter; Needs according to test; In the upper end and upper plate 3 joints of two limiters 2, put the cushion block I of same thickness, change pressure head 5 and give springs to be measured institute applied pressure.Cushion block II is used to adjust the spacing between front side board 6 and the back side panel 7.The diameter of the central through hole of cushion block II is greater than connecting the diameter that front side board 6 or back side panel 7 connect the through hole of base 1.Position at front side board 6 or back side panel 7 connection bases 1 is filled up the cushion block II of same thickness respectively, to adapt to the springs to be measured of different length.The diameter of the central through hole of cushion block III is identical with the diameter in the hole that the diameter of the center counterbore 62 of front side board 6 upsides, springs perforate end to be measured are opened; When springs to be measured is installed; With cushion block III be placed on springs perforate end to be measured above, through bolt cushion block III and springs perforate end to be measured are fixed on front side board 6 upper sides.
Shown in figure 11, for adopting the shape of the used springs to be measured of testing apparatus of the present invention.One end of springs to be measured has the hole, is used for being fixed together through the center counterbore 62 of nut with spring and front side board 6 upsides, limits the position of springs to be measured.The other end of springs to be measured places the groove 72 of the upside of back side panel 7.GB is recommended general tensile stress relaxation or the moment of flexure ring-shaped sample of adopting.The requirement of the sample that the present invention adopted meets testing apparatus provided by the present invention more, and is shown in figure 11, and the criterion of the design of the sample that the present invention adopted is: this sample is an equal stress sheet shape sample.Except that two termination discontinuity of sample, the suffered stress in each cross section equates in the gauge length scope.And according to the requirement of U.S. ASTME328 one 78 standards, when adopting wide sample, guarantee only to receive axial stress and do not produce lateral thrust, specimen width is 10 times of thickness at least.Specimen length selection principle: the amount of deflection that produces when making sample flexural deformation is measured easily.If too little then difficult measurement of amount of deflection.After sample marking distance surpasses certain size, in the time of just avoiding clamping to load, the influence of termination effect belt.If gauge length is oversize, can produce the surface normal error.The sample that the present invention adopts about the center line symmetry, can choose symmetric position and compare analysis.
The present invention provides the method for testing of a kind of springs normal temperature and high-temperature stress relaxation, and is shown in figure 12 based on above-mentioned testing apparatus, comprises the steps:
Step 1, the preparation of spring sample to be measured and processing.
Step 1.1: blanking, selected stress relaxation test material.
Step 1.2: the material warp is cut into the equal stress sample, and the equal stress sample is the schistose texture with symmetric shape, and an end of sample has the hole.Specimen shape shown in figure 11, the two ends of this spring sample to be measured are wide, and middle thin, two ends are the rectangle of two rules, and an end has the hole.
Step 1.3:, reach the mechanical state of regulation with the Ageing Treatment that sample is stipulated;
Step 2, the installation of testing equipment and test are prepared.
Step 2.1: will set the crooked primary stress of reed and bring the initial deflection computing formula into, and then the vertical drop of definite limiter 2 and front side board 6.The computing formula of the initial deflection f of spring sample to be measured is following:
f = L 2 · σ hE
Wherein, the unit of f is a millimeter (mm); L representes the gauge length of spring sample to be measured, and unit is mm; σ representes spring sample to be measured top layer maximum stress, and unit is MPa; H representes the thickness of spring sample to be measured, and unit is mm; E representes the elastic modulus of spring sample material to be measured, and unit is MPa.Desirable 0.5 σ of σ wherein e, 0.5 σ 0.2Or 0.8 σ e, σ 0.2The expression yield strength, σ eThe expression limit of elasticity.The present invention chooses 0.5 σ here 0.2, the present invention adopts this value, can access more initial degree of disturbing, thereby confirms a difference in height that is fit to test.
Step 2.2: described testing apparatus is installed.Front side board 6 and back side panel 7 are fixed on the base 1, then sample are fixed on the side plate of front and back.Afterwards two left and right limiters 2 are fixed on the base 1, then pressure transducer 4 are connected the back overall fixed on upper plate 3 with pressure head 5, through limiter 2 upper plate 3 and base 1 are fixed together at last.
When front side board 6 and back side panel 7 are separately fixed at front side and the rear side of base 1; Need adjust the spacing between front side board 6 and the back side panel 7 between front side board 6 and the base 1 and at the cushion block II that same thickness is set between back side panel 7 and the base 1 according to the length of spring sample to be measured; Described cushion block II has thickness and the center has through hole, and the diameter of through hole connects the diameter of the through hole of base 1 greater than front side board 6 or back side panel 7.
Spring sample to be measured is fixed on 6 last times of front side board, with cushion block III be placed on spring sample to be measured perforate one end above, through bolt cushion block III and spring sample to be measured perforate one end are fixed on the front side board 6 then.
During assembling limiter 2; The vertical drop that need obtain according to step 2.1; The downside of adjustment upper plate 3 is apart from the vertical range of the upper side of front side board 6; When the insufficient height of limiter 2, through the cushion block I that same thickness is set between two limiters 2 and upper plate 3 reach the height that will set; Described cushion block I has thickness and the center has through hole, and the diameter of through hole is greater than the diameter of limiter 2 upper ends.
Step 2.3: the sensor lead 8 that will connect pressure transducer 4 links to each other with external data presentation instrument; And the power lead and the power supply of data presentation instrument joined, be under zero test mode at described measuring equipment the data Displaying Meter is returned to zero and range calibration.
Step 2.4: tighten the nut of upper plate 3 and arranged on left and right sides stationary restraint 2, guarantee as far as possible in the rundown process that spring sample both sides are stressed evenly, after the data stabilization of pending data Displaying Meter, read primary stress;
Step 3; Carry out the spring stress relaxation test and gather the stress value of different time, specifically: the proving installation that will have sample to be tested is placed in the high-temperature test chamber energized; Regulate the temperature of chamber, the bending stress value of sheet sample under the record different time;
Step 4 reaches the regulation test period, reads the instrument displayed value of termination test during the time; From chamber, taking out testing apparatus cools off; With the testing apparatus unloading, take out sheet spring sample after the cooling, under free state, parked one hour; With the height of the recovery after the flexural deformation of strain-ga(u)ge measurement sheet spring, and then the stress relaxation damaed cordition of definite this reed material.The physical parameter of describing relaxation property has: residual stress lacks comparability; Relaxation rate (the drop-out value of unit interval internal stress; Describe the important parameter of relaxation property, constantly change, relevant with the microstructure of temperature primary stress and material) etc.; Calculate definitely according to test figure, accomplish springs stress relaxation is tested.
The springs stress relaxation method of testing that the present invention adopts can accurately be confirmed primary stress; Assess the mechanical property of this important parameter of primary stress and test material and contrast, the height of sample can be regulated through the cushion block of used testing equipment.Semi-girder has similar stress with conductive reed theoretically, and has overcome the maximum shortcoming of semi-girder test: deterministic force-amount of deflection and strain-stress relation time and the equipment to set up primary stress.The test equipment designs that is adopted is easy, and is indeformable under the high temperature, is easy to characteristics such as processing and measuring accuracy height; Realized the stress continuous coverage at a certain temperature of crooked springs; The sample one-step installation need not unloading midway until EOT, has reduced personal error.Owing to adopted high-precision pressure survey sensor and highly sensitive numeric display unit, thereby improved the precision of measurement data.Used pressure survey sensor 4 can adopt high-temperature-resistance pressure sensor according to request for utilization, realizes the continuous coverage purpose in the temperature required scope.
Springs stress relaxation sample is designed to variable cross section formula semi-girder mostly at present.This patent has designed the lax sample of equal stress, guarantees that sample only receives axial stress and do not produce lateral thrust.The selection of specimen length in addition, the influence of having avoided producing the termination effect belt that produces when clamping loads.Adopt all right comparative analysis equivalence of symmetrical sample position heterogeneous microstructure in addition.
The method of testing of flap elastics normal temperature provided by the invention and high temperature compressed stress relaxation; Height official post springs to be measured through control limiter 2 and side plate 6,7 produces constant crooked deformation, the sample of the thickness measure different length of the cushion block II of side plate 6,7 and base 1 junction before and after passing through in addition to regulate.Utilize the variation along with the prolongation stress value of time under different temperatures and primary stress situation of pressure transducer 4 monitoring springs to be measured, and then calculate sheet reed bending stress and relax.Adopt method of testing provided by the invention to measure the stress relaxation situation of change of springs normal temperature, high temperature, have simple to operation, reliable, the advantages such as measuring accuracy is higher, highly versatile of test.

Claims (9)

1. the method for testing of springs normal temperature and high-temperature stress relaxation is characterized in that, comprises the steps:
Step 1, the preparation of spring sample to be measured and processing;
Step 1.1: blanking, selected stress relaxation test material;
Step 1.2: the material warp is cut into the equal stress sample; Described equal stress sample is the schistose texture with symmetric shape, and an end of sample has the hole;
Step 1.3:, reach the mechanical state of regulation with the Ageing Treatment that spring sample to be measured is stipulated;
Step 2, the installation of testing apparatus and test are prepared;
Step 2.1: will set the crooked primary stress of reed and bring the initial deflection computing formula into, and confirm the vertical drop of limiter (2) and front side board (6);
Step 2.2: installation testing equipment; Described testing apparatus comprises: base (1), limiter (2), upper plate (3), pressure transducer (4), pressure head (5), front side board (6) and back side panel (7); In when assembling, at first, front side board (6) and back side panel (7) are separately fixed at the front side and the rear side of base (1), said front side board (6), back side panel (7) and base (1), being centered close on the same vertical horizontal line of three's downside; Secondly, through in the center counterbore (62) that is bolted to front side board (6) upside, the other end of spring sample to be measured is placed in the groove (72) in back side panel (7) upside centre position with an end of spring sample to be measured perforate; Then, pressure head (5) is fixed on the lower end of pressure transducer (4), the upper end of pressure transducer (4) is fixed on the central through hole (32) of upper plate (3), pressure transducer (4) is positioned at the downside of upper plate (3); At last; Assembling limiter (2); Left counterbore (11) that base (1) has and right counterbore (11), the left through hole (31) and the right through hole (31) of the vertical corresponding upper plate of difference (3), the left through hole (31) of described upper plate (3) and right through hole (31) are with respect to central through hole (32) left-right symmetric of upper plate; And base (1) is vertical corresponding with the center of upper plate (3); Assembling left limiter (2) between the left counterbore (11) of base (1) and the left through hole of upper plate (3) (31) assembles right limiter (2), the two ends band external thread of said limiter (2) between the right through hole (31) of the right counterbore (11) of base (1) and upper plate (3); The lower end is fixed in the left counterbore (11) or right counterbore (11) of base (1), and the upper end is through being bolted on left through hole of upper plate (3) (31) or the right through hole (31);
Step 2.3: the sensor lead (8) that will connect pressure transducer (4) links to each other with external data presentation instrument; And the power lead and the power supply of data presentation instrument joined, be under zero test mode at described measuring equipment the data Displaying Meter is returned to zero and range calibration;
Step 2.4: tighten the nut that upper plate (3) is gone up and arranged on left and right sides stationary restraint (2), guarantee as far as possible in the rundown process that spring sample to be measured both sides are stressed evenly, after the data stabilization of pending data Displaying Meter, read primary stress;
Step 3; Carry out the spring stress relaxation test and gather the stress value of different time, specifically: the proving installation that will have spring sample to be measured is placed in the high-temperature test chamber energized; Regulate the temperature of chamber, the bending stress value of sheet sample under the record different time;
Step 4 reaches the regulation test period, reads the instrument displayed value of termination test during the time; From chamber, taking out testing apparatus cools off; With the testing apparatus unloading, take out sample after the cooling, under free state, parked one hour; With the height of the recovery after the flexural deformation of strain-ga(u)ge measurement sheet spring, and then the stress relaxation damaed cordition of definite this reed material.
2. the method for testing of a kind of springs normal temperature according to claim 1 and high-temperature stress relaxation is characterized in that, the spring sample to be measured described in the step 1, the width of sample are 10 times of thickness at least.
3. the method for testing of a kind of springs normal temperature according to claim 1 and high-temperature stress relaxation is characterized in that, the initial deflection of spring sample to be measured in the step 2.1 is specifically confirmed through following formula:
Figure FDA0000156824010000021
Wherein, f representes the initial deflection value, and unit is a millimeter (mm); L representes the gauge length of spring sample to be measured, and unit is mm; σ representes spring sample to be measured top layer maximum stress, and unit is MPa; H representes the thickness of spring sample to be measured, and unit is mm; E representes the elastic modulus of spring sample material to be measured, and unit is MPa.
4. the method for testing of a kind of springs normal temperature according to claim 3 and high-temperature stress relaxation is characterized in that described σ gets 0.5 σ 0.2, σ 0.2The expression yield strength.
5. the method for testing of a kind of springs normal temperature according to claim 1 and high-temperature stress relaxation is characterized in that, the pressure head described in the step 2.2 (5) contacts with the centre position line of spring sample to be measured after the testing apparatus assembling is accomplished.
6. the method for testing of a kind of springs normal temperature according to claim 1 and high-temperature stress relaxation; It is characterized in that the specification of the pressure transducer described in the step 2.2 (4) is kz β k-1, output sensitivity is 2.248mV/V; Temperature range is 0 ℃~150 ℃, and range is 980N.
7. the method for testing of a kind of springs normal temperature according to claim 1 and high-temperature stress relaxation is characterized in that, the front side board described in the step 2.2 (6), and the bottom surface of the groove (72) of its upper side and back side panel (7) upside is in same horizontal level.
8. the method for testing of a kind of springs normal temperature according to claim 1 and high-temperature stress relaxation; It is characterized in that; Assembling limiter (2) described in the step 2.2, the vertical drop that need obtain according to step 2.1, the downside of adjustment upper plate (3) is apart from the vertical range of the upper side of front side board (6); When the insufficient height of limiter (2), through the cushion block I that same thickness is set between two limiters (2) and upper plate (3) reach the height that will set; Described cushion block I has thickness and the center has through hole, and the diameter of through hole is greater than limiter (2) upper end diameter.
9. the method for testing of a kind of springs normal temperature according to claim 1 and high-temperature stress relaxation; It is characterized in that; The front side and the rear side that front side board (6) and back side panel (7) are separately fixed at base (1) described in the step 2.2; Need adjust the spacing between front side board (6) and the back side panel (7) between front side board (6) and the base (1) and at the cushion block II that same thickness is set between back side panel (7) and the base (1) according to the length of spring sample to be measured; Described cushion block II has thickness and the center has through hole, and the diameter of through hole connects the diameter of the through hole of base (1) greater than front side board (6) or back side panel (7).
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CN108827779A (en) * 2018-09-12 2018-11-16 中国工程物理研究院核物理与化学研究所 A kind of the compression stress relaxation test device and test method of rubber material
CN109163867A (en) * 2018-06-29 2019-01-08 湖北省地震局 Leaf spring elastic characteristic detection device and its method under the conditions of Large Deflection Deformation
CN110068508A (en) * 2018-01-24 2019-07-30 宁波兴业盛泰集团有限公司 A kind of stress relaxation measuring device of copper strips
CN110873643A (en) * 2019-11-19 2020-03-10 北京航空航天大学 Accelerated storage life test system for planar spiral spring
CN112444459A (en) * 2020-11-17 2021-03-05 四川航天中天动力装备有限责任公司 Test equipment and method for stress relaxation test of engine wave spring
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CN103149105B (en) * 2013-03-06 2014-12-10 宁波金田铜业(集团)股份有限公司 Device and method for testing stress relaxation resistance of elastic belt material
CN104181051A (en) * 2013-05-27 2014-12-03 海洋王(东莞)照明科技有限公司 Spring testing method and spring elasticity testing device
CN103364182B (en) * 2013-06-26 2016-06-08 浙江理工大学 The device of flat spring rigidity is tested under a kind of hot environment
CN104596846A (en) * 2014-12-25 2015-05-06 中国科学院力学研究所 Method for correcting elasticity modulus and stress-strain curve in metal material compression test
CN104596846B (en) * 2014-12-25 2017-02-15 中国科学院力学研究所 Method for correcting elasticity modulus and stress-strain curve in metal material compression test
CN108152016A (en) * 2016-12-06 2018-06-12 凤城市凯驰内燃机配件有限公司 A kind of spring hot wire-CVD experimental rig
CN108384943A (en) * 2018-01-23 2018-08-10 武汉理工大学 A kind of Temperature-Stress coupled aging processing unit and its application method
CN110068508B (en) * 2018-01-24 2021-11-30 宁波兴业盛泰集团有限公司 Stress relaxation measuring device of copper strips
CN110068508A (en) * 2018-01-24 2019-07-30 宁波兴业盛泰集团有限公司 A kind of stress relaxation measuring device of copper strips
CN109163867A (en) * 2018-06-29 2019-01-08 湖北省地震局 Leaf spring elastic characteristic detection device and its method under the conditions of Large Deflection Deformation
CN109163867B (en) * 2018-06-29 2023-08-04 湖北省地震局 Device and method for detecting elastic characteristics of leaf spring under large-deflection deformation condition
CN108717023A (en) * 2018-07-17 2018-10-30 东北大学 The device and method of magnesium alloy plate and belt beaming limit and springback capacity is tested simultaneously
CN108717023B (en) * 2018-07-17 2023-10-27 东北大学 Device and method for simultaneously testing bending limit and resilience of magnesium alloy plate and strip
CN108827779A (en) * 2018-09-12 2018-11-16 中国工程物理研究院核物理与化学研究所 A kind of the compression stress relaxation test device and test method of rubber material
CN110873643A (en) * 2019-11-19 2020-03-10 北京航空航天大学 Accelerated storage life test system for planar spiral spring
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