CN101561380A

CN101561380A - Device and method for repeated bending tests under complex load

Info

Publication number: CN101561380A
Application number: CNA2009100845030A
Authority: CN
Inventors: 张永强; 刘兴全; 章军
Original assignee: Shougang Corp
Current assignee: Shougang Group Co Ltd
Priority date: 2009-05-18
Filing date: 2009-05-18
Publication date: 2009-10-21
Anticipated expiration: 2029-05-18
Also published as: CN101561380B

Abstract

The invention relates to a device and a method for repeated bending tests under complex load, which belong to the technical field of detection. The device comprises the following parts: a supporting system as a system framework, a tension loading system provided with two clamping devices for performing tension loading on a sample by fixing two ends of the sample on the clamping devices, a bending loading system provided with bending rollers for achieving the bending loading of the sample without changing the tension loading applied to two ends of the sample through an S-shaped bending passage formed by the bending rollers, an adjusting system for adjusting the distance between the bending rollers, and a control system which is connected with and controls the tension loading system and the bending loading system respectively so that the tension loading system and the bending loading system are controllable, wherein the bending loading system performs repeated bending on a sample target area fixed in the tension loading system so that the tensioning and the bending processes are loaded simultaneously and are broken and damaged in the target area. The invention also provides the method for performing the repeated bending tests under the complex load through the device.

Description

Repeated bending test equipment under the complex load and method

Technical field

The invention belongs to the detection technique field, particularly relate to repeated bending test equipment and method under a kind of complex load,, carry out the test of material repeated bending performance under complex load by the alternating bending test of strip specimen under complex load.

Background technology

Alternating bending test is to estimate a kind of important method of plastic deformation ability under thin plate or the strip alternating bending condition.

As shown in Figure 1, mostly traditional alternating bending test is to adopt fixes an end of sample 61, remainder penetrates in the projection 82 on the rocking arm 83, wherein rocking arm 83 is fixed on the worktable and can rotates around stationary shaft, arm 83 is shaken in the process of the test transfer makes bearing 81 bendings of sample 61 around predetermined radius, rotate the alternating bending test method of rocking arm 83 more in opposite direction, this method can be measured the plastic deformation ability in the material alternating bending process.

The deficiency of said method is that it only can the bending property of test material under free state.Material usually is the alternating bending of carrying out under the complex load situation in the engineering, as the alternating bending of carrying out under constant or cyclic loading form.And under loading, the repeated bending performance of material can change a lot.

Be the compound bending performance of test material under load condition, recently certain methods attempts to load at the sample two ends, for example application number is that 200720074944.9 utility model patent has been described a kind of band steel bend test device, it realizes the alternating bending test of band steel under the load by the acting in conjunction of gravity and spring force.

The deficiency of said method is when bending under the effect of steel band in dancer roll, because being subjected to the length of tension force effect spring can change, the variation of loaded load is subjected to the restriction of spring Hooke's law in the BENDING PROCESS, i.e. single and the crooked loading and the loading mutual interference mutually that stretches of load mode.Secondly, said method is by two pairs of stationary roll clamping steel bands, and in the compound bending process of the test, retained part is also bending simultaneously, and the destruction of material might occur in retained part, and causes test findings to lose efficacy.

In addition, all supporting bending die (for example bearing in the classic method 81 or application number are the dancer roll 3 of different-diameter in 200720074944.9 utility model patents) that different curvature radius is arranged in the existing bending test equipment.For measuring the performance under the differently curved radius, must change bending die as required.Complete bending die can increase equipment cost, and die change can increase test period and complicacy in the test simultaneously.

Summary of the invention

The object of the present invention is to provide repeated bending test equipment and method under a kind of complex load, overcome above-mentioned deficiency, make alternating bending test can simulation material be carried out alternating bending under the engineering actual conditions state.Realized: 1) tensile load and bending load can independently controlled loading; 2) tensile load process influence by bending not; 3) destruction of material occurs in the target area; 4) exploitation can be satisfied the bending die of different tests demand, saves cost and test period and short form test.

Equipment of the present invention comprises: support system, as system framework; The stretching loading system has two clamp devices, is respectively fixed to described clamp device and to the sample loading that stretches by the two ends with sample; Crooked loading system has bending roll, and the serpentine bending channel that sample forms by bending roll carries out crooked loading and do not change the tensile load that is applied to the sample two ends sample with realization; Adjustment System is used for adjusting the distance between the bending roll; And control system, the stretching loading system is connected with control system respectively with crooked loading system and by its control, loading and crooked loading procedure are independent controlled so that stretch, wherein, crooked loading system is carried out alternating bending to the target area of the sample that is fixed in the stretching loading system, so that stretch and bending loads simultaneously and rupture failure occurs in the target area.

Preferably, crooked loading system also comprises bending table, bending table leading screw, coupling arrangement and chute, and worktable is realized alternating bending along guide screw movement so that sample moves along the serpentine passage.

Preferably, at least one in the clamp device applies tensile load under the control system effect.

Preferably, Adjustment System comprises adjusting lever, adjusting gear and stationary installation, by adjusting gear change in chute and with bending roll that coupling arrangement links to each other between distance, make sample not bend, and only when passing through bending roll, bend at the clamp device place.

Preferably, described equipment has at least two bending rolls.

Preferably, support system comprises crossbeam and column, and this column is as the guide piece of bending table motion.

Preferably, control system comprises crooked transmission gear for electric motor, crooked motor, stretching topworks, controller.

Preferably, bending roll has circular cross section.

Preferably, bending roll has the cam-like cross section, and the cam-like cross section is designed the circular arc of multiple radius-of-curvature, its adjustable angle, so that sample under differently curved radius alternating bending takes place, cam-like bending roll angle is determined by the locking device location.

Another object of the present invention provides a kind ofly carries out the test method that alternating bending takes place simulation material by above-mentioned bending apparatus under complex load, it may further comprise the steps:

(1) specimen preparation: measured material is processed into strip specimen, and the specimen preparation process need guarantee that tested part is positioned at the target area of sample, i.e. the middle part of sample;

(2) choose the bending roll radius: according to the test needs, determine suitable bending radius, choose corresponding bending roll, wherein selected bending roll radius can be identical, also can be different;

(3) bending roll location: first bending roll, second bending roll are installed in the chute of bending table, and the distance by between coupling arrangement and two bending rolls of adjusting gear adjustment makes the sample two ends be positioned on the axis of contiguous clamp device;

(4) wear band: strip specimen is passed bending roll make it form serpentine, and sample two ends and clamp device are linked;

(5) setting program: with bending table upper and lower extreme position once back and forth be the cycle, with the desired stress input controller of strip specimen, and the setting program done state, as the designated cycle number of times or until the record number of times etc. that fractures;

(6) sample is carried out alternating bending: executive routine, under the complex load situation, finish the alternating bending of strip specimen, until end.

Preferably, involved sample is uniform single material in this method.

Preferably, involved sample is the material that has weld seam and coating in this method.

Preferably, this method is used for the compound bending performance test of thin plate under load load.

Description of drawings

Fig. 1 is the tradition synoptic diagram of bending method repeatedly.

Fig. 2 is the synoptic diagram according to the repeated bending test equipment of first embodiment of the invention.

Fig. 3 is the total system parts relative position synoptic diagram when arriving the limes superiors positions of the bending table 32 in the repeated bending test equipment of Fig. 2.

Fig. 4 is the total system parts relative position synoptic diagram when arriving the smallest limit positions of the bending table 32 in the repeated bending test equipment of Fig. 2.

The interval synoptic diagram of the different stresses that Fig. 5 stands on whole length for sample 61.

Fig. 6 is first bending roll 36, second bending roll, 37 structures and a position view in the second embodiment of the invention, and the

bending roll

36,37 among second embodiment has the cam-like cross section.

Embodiment

Below the term of using in the explanation " level ", " vertically ", " up and down " etc. all is in order exemplarily to describe embodiments of the present invention, and is not intended to limit concrete orientation of the present invention.

Be described further below in conjunction with accompanying drawing 2:

Repeated bending test equipment under the complex load comprises support system 1, stretching loading system 2, crooked loading system 3, Adjustment System 4 and control system 5.

Support system 1 comprises crossbeam 11 and column 12.Wherein, crossbeam 11 is made by rigid material, is flatly settled in the present embodiment, does not occur bending and deformation under stressing conditions.Column 12 is made by rigid material, vertically settles in the present embodiment, is supporting crossbeam 11; Simultaneously, column 12 can be used as the guide piece of bending table 32, and its surface is processed to the low smooth surface of friction factor, and bending table 32 can slide along the column easy on and off.

Stretching loading system 2 comprises first clamp device 21, second clamp device 22 and stretching worktable 23.In the present embodiment, stretching loading system 2 has two

clamp devices

21 and 22, is respectively applied for the two ends of clamping strip specimen 61.Wherein, first clamping device 21 is fixed on the crossbeam 11, and second clamping device is fixed on the stretching worktable 23, and both are offset a distance L in the horizontal direction.In the present embodiment, stretching worktable 23 is flatly placed.

Crooked loading system 3 comprises first bending roll 36, second bending roll 37, bending table 32, bending table leading screw 33, coupling arrangement 34 and chute 35.

Bending roll

36,37 places the chute 35 of bending table 32, and by linking such as bearing such bindiny mechanism and coupling arrangement 34.Bending table 32 links with bending table leading screw 33, and along with 33 rotations of bending table leading screw, bending table 32 moves along vertical direction under the guide effect of column 12.According to the present invention, the quantity of

bending roll

36,37 is at least two, so that form at least one serpentine bending channel between bending roll 36,37.The strip specimen 61 that crooked loading duration, two ends are clamped on the

clamp device

21,22 forms the serpentine bending via rotating bending roll 36,37.In the present embodiment, when bending table 32 to-and-fro movements, make the bending of two bending rolls of one section interval experience on the sample 61, i.e. to-and-fro movement by bending table makes sample 61 move in the serpentine passage with the realization alternating bending.Wherein, the zone of sample 61 generation compound bendings is called as the target area.It is pointed out that equipment will provide a series of bending rolls with different radii usually in order to satisfy the needs of alternating bending under the differently curved radius.Select first bending roll 36 and the 37 complete uses of second bending roll of same radius, can realize the alternating bending of symmetry under the same radius; Select different radii first bending roll 36 and the 37 complete practicalities of second bending roll, can realize two compound bendings that the bending direction bending radius is different, satisfying special on-the-spot crooked situation, as be used for the crooked situation simulation of steel rolling production-line.

Adjustment System 4 comprises adjusting lever 41, adjusting gear 42 and stationary installation 43.The effect of Adjustment System is: by adjusting the distance between the

bending roll

36,37, the part that makes sample 61 stretch out from first clamp device 21 and second clamp device 22 is positioned on the extended line that the sample adjacent end portion is held part, sample 61 is held the position and does not bend at loading duration, guarantees that sample destruction occurs in the target area of alternating bending.In the present embodiment, for realizing above-mentioned adjustment purpose, the stationary installation 43 that is connected on the bending table 32 has internal thread; Adjusting lever has external thread, and its external thread matches with the internal thread of stationary installation 43; The coupling arrangement 34 that links to each other with

bending roll

36,37 is designed to hollow structure, and its internal diameter is greater than the adjusting lever radius of fillet, so that adjusting lever can pass coupling arrangement; Adjusting gear 42 can match with the external thread of adjusting lever for having female thread structure.During adjustment, with stationary installation 43 that adjusting lever 42 is fixing earlier, and then pass through adjusting gear 42 with each

bending roll

36,37 locking.In the present embodiment, defining the first bending roll radius is R1, the second bending roll radius is R2, distance between the two bending roll axle center is L1, for satisfying above-mentioned requirements, need guarantee R1+L1+R2=L, and sample 61 is positioned on the extended line that the sample adjacent end portion is held part (as shown in Figure 2) from the part of stepping up device 21 and stretching out.

Control system 5 comprises crooked transmission gear for electric motor 51, crooked motor 52, stretching topworks 53 and controller 54.Stretching topworks 53 links with stretching worktable 23, and the topworks 53 that stretches in the present embodiment is hydraulic mechanism.Along with the motion of stretching topworks, the stretching worktable can move up and down.Crooked motor 52 links with bending table leading screw 33 by crooked transmission gear for electric motor 51.Crooked motor 52 all links with controller 54 with stretching topworks 53.Gearing 51 in the control system can be traditional mechanisms such as chain, gear, belt, but need to prove and be to guarantee loading accuracy, gearing 51 need with motion synchronously such as motor shaft, leading screw, have and avoid the characteristic of skidding.The effect of controller 54 is the speed of the crooked motor 52 of control and the tension force of stretching topworks 53.By control stretching topworks 53, make the strip specimen 61 be clamped between two

clamp devices

21 and 22 and pass

bending roll

36,37 be subjected to the effect of multi-form tension force, as permanent load, period T 1 load etc.By controlling crooked motor 54, can be so that bending table 32 pump, thus make the sample 61 through two

bending rolls

36,37 be subjected to the alternating bending effect.By adjusting crooked motor 52, can change crooked period T 2.When control system 5 keeps tensile force constant, can realize the alternating bending test under the permanent load; As control system 5 control stretching magnitudes of load, period T 1 and flexure cycles T2, and be used the

bending roll

36,37 of different radii, can realize the alternating bending test under the above-mentioned various complex load.Control system 5 is loaded on sample 61 by stretching worktable 23 and

clamp device

21,22 with tension force; Simultaneously, control system 5 by bending table leading screw 33, bending table 32 with flecition to sample 61.

The residing position of parts of entire equipment when Fig. 3 and Fig. 4 show bending table 32 respectively and reach limes superiors position and smallest limit position.

According to the differently curved form that sample 61 experiences in the whole circulation process, the stress of sample 61 is classified.As shown in Figure 5, according to the difference of stress, the sample 61 between first clamp device 21 and second clamp device 22 is divided into five intervals of 71-75 from top to bottom.In the round dust cycle of bending table 32 between upper and lower extreme position,

interval

71 and 75 do not produce any bending, are the pure extension district; Twice bending taken place in the each point in

interval

72 and 74, and bending direction is identical, and bend in one direction has promptly taken place; Four bendings have taken place in the each point in interval 73, and the bending direction in each one way (half period) is opposite, and alternating bending has promptly taken place.Investigate the mechanical behavior of strip specimen 61 each section in 71-75, because the number of bends of steel bands is many in 73 zones, and curve form is compound bending, is the easiest ruined link of material therefore, also is the target area that this Apparatus and method for is investigated.

Equipment of the present invention can be realized strip specimen, coating sample and the strip specimen that has a weld seam are detected in the repeated bending performance under the complex load, when the sample that has weld seam is tested, advantageously, weld seam need be placed between effective detection zone in 73.

Need to prove that

bending roll

36,37 quantity among the embodiment of the present invention are two, can be more than two in the actual use according to the required bending roll quantity of curve form.

In the second embodiment of the invention,

bending roll

36,37 is designed to the bending roll that the cross section is a cam-like, and other parts are similar to first embodiment.Be simplified illustration, only provide first bending roll 36, second bending roll, 37 structures and position view (Fig. 6) among second embodiment, remainder omits.Similarly, be simplified illustration, have two sections circular arcs that radius-of-curvature is different on the cam-like bending roll of present embodiment shown in Fig. 6, be respectively r1 and r2,

bending roll

36 and 37 designs have a plurality of pilot holes 93 around crooked roll shaft central distribution, change the angle of bending roll cam and, can select different bending radius with as fixing in locking devices such as the pin 95 insertion pilot holes 93.When selecting differently curved radius as needs, only need to change first bending roll 36, second bending roll 37 angle and can with locking device 95 positioning instants.According to actual needs, the radius of

bending roll

36,37 cams can be designed as more a plurality of, can replace the

bending roll

36,37 of a series of different radiis among first embodiment in this way, thereby saves accessory cost and roll changing time.

According to equipment of the present invention, propose to make strip specimen 61 in the serpentine passage that first bending roll 36, second bending roll 37 form, to move, stretch and bending load by the control sample, realize the test method of sample alternating bending under the complex load mode.

The step of alternating bending test method is under the complex load described in the invention:

(1) specimen preparation: measured material is processed into strip specimen 61, and the specimen preparation process need guarantee that tested part is positioned at the target area 73 of sample 61, the i.e. middle part of sample;

(2) choose the bending roll radius: according to the test needs, determine suitable bending radius, choose corresponding first bending roll 36, second bending roll 37, wherein selected first bending roll 36, second bending roll, 37 radiuses can be identical, also can be different;

(3) bending roll location: first bending roll 36, second bending roll 37 are installed in the chute 35 of bending table 32, distance by coupling arrangement 34 and adjusting gear 42 are adjusted between two bending rolls makes the two ends of sample 61 be positioned on the axis of

contiguous clamp device

21,22;

(5) setting program: with bending table upper and lower extreme position once back and forth be the cycle, with the desired stress input controller 54 of strip specimen 61, and the setting program done state, as the designated cycle number of times or until the record number of times etc. that fractures;

(6) sample is carried out alternating bending: executive routine, under the complex load situation, finish the alternating bending of strip specimen 61, until end.

Preferably, involved sample 61 is uniform single materials in this method.

Preferably, involved sample 61 is the materials that have weld seam and coating in this method.

Although described the present invention by example, but what it will be apparent to those skilled in the art that is, the only also unrestricted the present invention for explaination purpose of the present invention of above present embodiment, those skilled in the art can make various modifications, change and replacement under the situation that does not depart from the spirit and scope of the invention that is defined by the following claims.

Claims

1, the repeated bending test equipment under a kind of complex load comprises support system (1), stretching loading system (2), crooked loading system (3), Adjustment System (4) and control system (5); It is characterized in that,

Support system (1) is as system framework;

Stretching loading system (2) has two clamp devices (21,22), is respectively fixed to described clamp device (21,22) and to the sample loading that stretches by the two ends with sample (61);

Crooked loading system (3), at least have 2 bending rolls (36,37), the serpentine bending channel that sample (61) forms by first bending roll (36) and second bending roll (37) carries out crooked loading and does not change the tensile load that is applied to the sample two ends sample with realization;

Adjustment System (4) is used for adjusting the distance between first bending roll (36) and second bending roll (37);

And control system (5), stretching loading system (2) is connected with control system (5) respectively with crooked loading system (3) and by its control, loading and crooked loading procedure are independent controlled so that stretch, crooked loading system (3) is carried out alternating bending to the target area of the sample (61) that is fixed in stretching loading system (2), so that stretch and bending loads simultaneously and rupture failure occurs in the target area.

2, equipment as claimed in claim 1, it is characterized in that, described crooked loading system (3) also comprises bending table (32), bending table leading screw (33), coupling arrangement (34) and chute (35), worktable is realized alternating bending along guide screw movement so that sample (61) moves along the serpentine passage.

3, equipment as claimed in claim 1 is characterized in that, at least one in the described clamp device (21,22) applies tensile load under control system (5) effect.

4, equipment as claimed in claim 1, it is characterized in that, described Adjustment System (4) comprises adjusting lever (41), adjusting gear (42) and stationary installation (43), change first bending roll (36) in chute (35) and with coupling arrangement (34), link to each other and the distance between second bending roll (37) by adjusting gear (42), make sample (61) not locate to bend, and only bending through bending roll (36,37) time at clamp device (21,22).

As claim 1 or 4 described equipment, it is characterized in that 5, described bending roll (36,37) has circular cross section.

6, equipment as claimed in claim 1 is characterized in that, described support system (1) comprises crossbeam (11) and column (12), and this column is as the guide piece of bending table (32) motion.

7, equipment as claimed in claim 1 is characterized in that, described control system (5) comprises crooked transmission gear for electric motor (51), crooked motor (52), stretching topworks (53), controller (54).

8, as claim 1 or 4 described equipment, it is characterized in that, bending roll (36,37) has the cam-like cross section, the cam-like cross section is designed to have the circular arc of multiple radius-of-curvature, its adjustable angle, so that sample (61) under differently curved radius alternating bending takes place, cam-like bending roll (36,37) angle is determined by locking device (95) location.

9, a kind of method that adopts the described equipment of claim 1 to carry out the alternating bending test under the complex load is characterized in that, may further comprise the steps:

(1) specimen preparation: measured material is processed into strip specimen (61), and the specimen preparation process need guarantee that tested part is positioned at the target area of sample (61) (73), the i.e. middle part of sample;

(2) choose bending roll (36,37) radius: according to the test needs, determine suitable bending radius, choose corresponding bending roll, wherein selected bending roll radius is identical, or different;

(3) bending roll (36,37) location: first bending roll (36), second bending roll (37) are installed in the chute (35) of bending table (32), distance by between coupling arrangement (34) and two bending rolls of adjusting gear (42) adjustment makes sample (61) be positioned on the axis of adjacent clamp device (21,22);

(5) setting program: with bending table upper and lower extreme position once back and forth be the cycle, with the desired stress input controller (54) of strip specimen (61), and the setting program done state, designated cycle number of times or until the record number of times that fractures;

(6) sample is carried out alternating bending: executive routine, under the complex load situation, finish the alternating bending of strip specimen (61), until end.

10, method as claimed in claim 9 is characterized in that, described sample (61) is uniform single material.

11, method as claimed in claim 10 is characterized in that, described sample (61) is the material that has weld seam and coating.

12, method as claimed in claim 10 is characterized in that, this method is used for the compound bending performance test of thin plate under load load.