CN104913988A - Hopkinson principle-based concrete axial tensile strength measuring method - Google Patents
Hopkinson principle-based concrete axial tensile strength measuring method Download PDFInfo
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- CN104913988A CN104913988A CN201510237759.6A CN201510237759A CN104913988A CN 104913988 A CN104913988 A CN 104913988A CN 201510237759 A CN201510237759 A CN 201510237759A CN 104913988 A CN104913988 A CN 104913988A
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Abstract
The invention discloses a Hopkinson principle-based concrete axial tensile strength measuring method. The method adopts a Hopkinson pressure bar device to carry out the axial tensile strength measurement of a concrete test piece (10), and the method comprises the following steps: removing a transmission bar in the Hopkinson pressure bar device; arranging a plurality of groups of foil gauges (50) in positions having different distances to the bump end of the test piece (10); arranging an accelerometer (30) at the free end (11) of the concrete axial test piece (10); analyzing an oscillogram obtained through monitoring by the accelerometer (30) to obtain the acceleration of the test piece free end (11); calculating to obtain the speed of the surface of the test piece free end (11); and measuring the speed of the test piece free end (11), and calculating and analyzing to obtain the axial tensile strength of the concrete test piece (10). The method allows the concrete axial tensile strength to be accurately measured and calculated under high strain rate.
Description
Technical field
The present invention relates to the measuring method of concrete axial tensile strength, particularly relate to a kind of concrete axial tensile strength measuring method based on Hopkinson principle.
Background technology
Concrete material is the most general building materials, is widely applied in various industry.Under the effect of the high speed loads such as blast, impact, need to know that concrete axial tensile strength is to determine the accidental load that concrete can bear exactly.At present, in measurement concrete axial tensile strength, usually the method mainly hydraulic servo experimental system adopted both at home and abroad, but be only limitted under the condition of general low strain dynamic rate, measurement for the concrete axial tensile strength under the condition of higher rate of strain is also very difficult, mainly because mean that the pulse of incident wave wants amplitude low under higher rate of strain condition, lasts length, but the length of incident bar is inadequate, thus causes incident wave and reflection wave overlapped signal to be difficult to process.The concrete axial tensile strength measuring method that another generally adopts is strain gauge method.This method directly pastes foil gauge on concrete sample, by the maximal value of tensile strain that foil gauge is directly recorded to, under the prerequisite of the hypothesis of material, by the product of tensile strain maximal value and the elastic modulus tensile strength as material, but, along with the increase of fracture position distance, reflecting tensile stress obviously reduces, the tensile strength of concrete material can not be represented at the transmitting tension crest value measured away from fracture position, therefore, the defect of this measuring method is: be only applicable to low strain dynamic rate condition, and the concrete axial tensile strength that cannot be applied under middle high strain-rate condition is measured.
Summary of the invention
The object of the invention is to the defect overcoming prior art, a kind of concrete axial tensile strength measuring method based on Hopkinson principle be provided, can under middle high strain-rate condition exactly meter calculate the tensile strength of the concrete axial heart.
In order to solve the problems of the technologies described above, the present invention by the following technical solutions:
A kind of concrete axial tensile strength measuring method based on Hopkinson principle, the axial tensile strength adopting Hopkinson pressure bar device to carry out concrete sample is measured, comprise concrete sample, incident bar, bullet, foil gauge, it is characterized in that: the transmission bar in the Hopkinson pressure bar device described in removal; Described test specimen impingement distance end place is provided with array foil gauge; At the free end of described concrete axial test specimen, an accelerometer is set; The analysis of oscillogram monitored by described accelerometer draws the acceleration of described test specimen free end; Calculate the speed of described test specimen free end surface; Measure the speed of described test specimen free end, then measured the tensile strength in described concrete sample axle center by computational analysis.
Measuring method of the present invention specifically comprises the following steps:
(1) accelerometer is set at described test specimen free end, and is connected with a data collecting instrument by a bridge box;
(2) perpendicular end surface of the vertical plane of described incident bar butt end and the shock end of described concrete sample is fit together;
(3) with the end of described projectile impact incident bar, measured the oscillogram of the ripple passed in described test specimen by the array foil gauge that test specimen is arranged, and measure the acceleration diagram of test specimen free end with described accelerometer;
(4) by the figure measured by described array foil gauge, according to formula
calculate wave velocity C
0, wherein, L is the length of test specimen, and Δ t refers to that incident wave enters test specimen to test specimen free end institute's time spent;
Then according to formula
calculate concrete dynamic elastic modulus E, wherein E refers to the concrete dynamic modulus of elasticity, and ρ refers to the density of concrete sample;
According to formula
ask for the dependent variable ε of described test specimen, wherein Δ L represents the elongation of concrete sample, Δ u represents the variable quantity starting to occur speed in the moment of drawing stress to the time interval of fracture at test specimen, is that the pattern fits collected by the accelerometer of free end is drawn;
Again further according to formula σ=E ε, extrapolate stress
(5) according to formula
calculate rate of strain, wherein t
prepresent that test specimen starts to occur the time interval of the moment of drawing stress to fracture;
(6) adjust described bullet inject the size of air pressure, repeat above-mentioned (3)-(5) step, ask for the rate of strain under different air pressure conditions and different strain rate condition respectively, finally draw the axial tensile strength-rate of strain relation curve of described concrete axial test specimen.
Preferably, described test specimen impingement distance end place is provided with 3 groups of foil gauges, is separately positioned on described test specimen impingement distance end 100mm, 200mm, 300mm place.
Wherein, the foil gauge in described often group is connected mutually, then often organizes foil gauge and is connected with the respective input difference serial of described bridge box, then be connected with the serial of data acquisition unit instrument by bridge box.
Preferably, described concrete axial test specimen is of a size of diameter 74mm, length 500mm.
Preferably, the length of described bullet is 100mm.
Compared with prior art, the present invention has the following advantages and beneficial effect:
1. the present invention the scope that is suitable for wide, be not only applicable to low strain dynamic rate condition, the concrete axial tensile strength be particularly useful under middle high strain-rate condition is measured.
2. measurement result precision is high; Easily tensile strength is determined when test specimen repeatedly ruptures; Maximum tensile stress and actual conditions meet.
3. experimental result can not only obtain spallation strength, can also obtain the relevant information such as damage development in spallation process.
Accompanying drawing explanation
Fig. 1 is the measurement installation diagram of measurement mechanism incident bar of the present invention, test specimen and accelerometer.
Fig. 2 is the Acceleration pulse schematic diagram that accelerometer of the present invention collects.
Fig. 3 is the waveform schematic diagram of the speed that the Acceleration pulse according to Fig. 2 obtains.
Fig. 4 is the graph of relation of stress-time of the present invention.
Fig. 5 is concrete axial test specimen axial tensile strength-rate of strain graph of relation of the present invention.
Wherein, 10 concrete axial test specimens, 11 test specimen free ends, 20 incident bars, 30 accelerometers, 40 bullets, 50 foil gauges, 60 bridge boxes, 70 data collecting instruments.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in further details.
The present invention is based on the concrete axial tensile strength measuring method of Hopkinson principle, the axial tensile strength adopting Hopkinson pressure bar device to carry out concrete sample (10) is measured, as shown in Figure 1, comprise concrete sample (10), incident bar (20), bullet (40), foil gauge (50), it is characterized in that: the transmission bar in the Hopkinson pressure bar device described in removal; At described test specimen (10) impingement distance end, place is provided with array foil gauge (50); At the free end (11) of described concrete axial test specimen (10), an accelerometer (30) is set; The analysis of oscillogram monitored by described accelerometer (30) draws the acceleration of described test specimen free end (11); Calculate the speed on described test specimen free end (11) surface; Measure the speed of described test specimen free end (11), then measured the tensile strength in described concrete sample (10) axle center by computational analysis.
Measuring method of the present invention comprises the following steps:
(1) accelerometer (30) is set at described test specimen free end (11), and is connected with a data collecting instrument (70) by a bridge box (60); In practical operation, after concrete sample free end (11) is stained with accelerometer (30), is first connected with bridge box (60), then is connected with data collecting instrument (70).
(2) perpendicular end surface of the vertical plane of described incident bar (20) butt end and the shock end of described concrete sample (10) is fit together;
(3) end of incident bar (20) is clashed into described bullet (40), the oscillogram of the ripple passed in described test specimen (10) is measured by the upper array foil gauge (50) arranged of test specimen (10), and the acceleration diagram of test specimen free end (11) is measured with described accelerometer (30), Fig. 2 is the Acceleration pulse schematic diagram that accelerometer of the present invention collects.
As shown in Figure 3, be the waveform schematic diagram of the speed that the Acceleration pulse according to Fig. 2 obtains: can speed v be obtained by formula:
wherein a represents acceleration, and t represents the time, and described Fig. 3 curve is obtained by software matching according to this formula.
(4) by figure--the graph of relation of the stress-time shown in Fig. 4 measured by described array foil gauge (50), then
According to formula
calculate wave velocity C
0, wherein, L is the length of test specimen, and Δ t refers to that incident wave enters test specimen to test specimen free end institute's time spent;
Then according to formula
calculate concrete dynamic elastic modulus E, wherein E refers to the concrete dynamic modulus of elasticity, and ρ refers to the density of concrete sample;
According to formula
ask for the dependent variable ε of described test specimen (10), wherein Δ L represents the elongation of concrete sample, Δ u represents the variable quantity starting to occur speed in the moment of drawing stress to the time interval of fracture at test specimen, is that the pattern fits collected by the accelerometer of free end (11) is drawn;
Again further according to formula σ=E ε, extrapolate stress
(5) according to formula
calculate rate of strain, wherein t
prepresent that test specimen starts to occur the time interval of the moment of drawing stress to fracture;
(6) adjust described bullet (40) inject the size of air pressure, repeat above-mentioned (3)-(5) step, ask for the rate of strain under different air pressure conditions and different strain rate condition respectively, finally draw the axial tensile strength-rate of strain relation curve of described concrete axial test specimen (10), as shown in Figure 5.
Preferably, described test specimen (10) impingement distance end place is provided with 3 groups of foil gauges (50), is separately positioned on described test specimen (10) impingement distance end 100mm, 200mm, 300mm place.
Wherein, foil gauge (50) in described often group is connected mutually, then often organize foil gauge (50) to be connected with the respective input difference serial of described bridge box (60), then bridge box (60) is connected with data acquisition unit instrument (70) serial.
Preferably, described concrete axial test specimen (10) is of a size of diameter 74mm, length 500mm.
Preferably, the length of described bullet (40) is 100mm.
Principle of the present invention is: removed by the transmission bar in original Hopkinson experimental provision, and paste an accelerometer at the free end of test specimen, then the ripple monitored by accelerometer analyzes the acceleration of concrete sample free end, the speed of test specimen free end surface can calculating by acceleration signal, to ensure the speed accurately measuring test specimen free end, the tensile strength in concrete axle center then can be measured by computational analysis.
Claims (6)
1. the concrete axial tensile strength measuring method based on Hopkinson principle, the axial tensile strength adopting Hopkinson pressure bar device to carry out concrete sample (10) is measured, comprise concrete sample (10), incident bar (20), bullet (40), foil gauge (50), it is characterized in that: the transmission bar in the Hopkinson pressure bar device described in removal; At described test specimen (10) impingement distance end, place is provided with array foil gauge (50); At the free end (11) of described concrete axial test specimen (10), an accelerometer (30) is set; The analysis of oscillogram monitored by described accelerometer (30) draws the acceleration of described test specimen free end (11); Calculate the speed on described test specimen free end (11) surface; Measure the speed of described test specimen free end (11), then measured the tensile strength in described concrete sample (10) axle center by computational analysis.
2. a kind of concrete axial tensile strength measuring method based on Hopkinson principle according to claim 1, is characterized in that comprising the following steps:
(1) accelerometer (30) is set at described test specimen free end (11), and is connected with a data collecting instrument (70) by a bridge box (60);
(2) perpendicular end surface of the vertical plane of described incident bar (20) butt end and the shock end of described concrete sample (10) is fit together;
(3) end of incident bar (20) is clashed into described bullet (40), measured the oscillogram of the ripple passed in described test specimen (10) by the upper array foil gauge (50) arranged of test specimen (10), and measure the acceleration diagram of test specimen free end (11) with described accelerometer (30);
(4) by the figure measured by described array foil gauge (50), according to formula
calculate wave velocity C
0, wherein, L is the length of test specimen, and Δ t refers to that incident wave enters test specimen to test specimen free end institute's time spent;
Then according to formula
calculate concrete dynamic elastic modulus E, wherein E refers to the concrete dynamic modulus of elasticity, and ρ refers to the density of concrete sample;
According to formula
ask for the dependent variable ε of described test specimen (10), wherein Δ L represents the elongation of concrete sample, Δ u represents the variable quantity starting to occur speed in the moment of drawing stress to the time interval of fracture at test specimen, is that the pattern fits collected by the accelerometer of free end (11) is drawn;
Again further according to formula σ=E ε, extrapolate stress
(5) according to formula
calculate rate of strain, wherein t
prepresent that test specimen starts to occur the time interval of the moment of drawing stress to fracture;
(6) adjust described bullet (40) inject the size of air pressure, repeat above-mentioned (3)-(5) step, ask for the rate of strain under different air pressure conditions and different strain rate condition respectively, finally draw the axial tensile strength-rate of strain relation curve of described concrete axial test specimen (10).
3. a kind of concrete axial tensile strength measuring method based on Hopkinson principle according to claim 1, it is characterized in that: described test specimen (10) impingement distance end place is provided with 3 groups of foil gauges (50), be separately positioned on described test specimen (10) impingement distance end 100mm, 200mm, 300mm place.
4. a kind of concrete axial tensile strength measuring method based on Hopkinson principle according to claim 1 or 3, it is characterized in that: the foil gauge (50) in described often group is connected mutually, then often organize foil gauge (50) to be connected with the respective input difference serial of described bridge box (60), then bridge box (60) is connected with data acquisition unit instrument (70) serial.
5. a kind of concrete axial tensile strength measuring method based on Hopkinson principle according to claim 1, is characterized in that: described concrete axial test specimen (10) is of a size of diameter 74mm, length 500mm.
6. a kind of concrete axial tensile strength measuring method based on Hopkinson principle according to claim 1, is characterized in that: the length of described bullet (40) is 100mm.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105928808A (en) * | 2016-07-01 | 2016-09-07 | 河海大学 | Measuring and determining method for spall strength of quasi-brittle material at high strain rate |
| CN106093194A (en) * | 2016-06-03 | 2016-11-09 | 河海大学 | The test device of the lower quasi-brittle material stress wave attentuation rule of blast and amount levy method |
| CN107228802A (en) * | 2017-06-15 | 2017-10-03 | 东北大学 | A kind of SHPB devices and its application method for obtaining half-sine wave under different loading speeds |
| CN116380619A (en) * | 2022-12-26 | 2023-07-04 | 中国人民解放军军事科学院国防工程研究院工程防护研究所 | Method for determining residual spalling strength of steel fiber concrete under repeated impact load |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0849583A1 (en) * | 1996-12-12 | 1998-06-24 | European Community | Split Hopkinson bar testing apparatus |
| CN102879261A (en) * | 2012-09-28 | 2013-01-16 | 北京理工大学 | Reluctance-type miniature Hopkinson tension and pressure integrated bar device |
| CN103134750A (en) * | 2013-02-01 | 2013-06-05 | 河海大学 | Steel bar drawing testing device suitable for Hopkinson pressure bar |
-
2015
- 2015-05-11 CN CN201510237759.6A patent/CN104913988B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0849583A1 (en) * | 1996-12-12 | 1998-06-24 | European Community | Split Hopkinson bar testing apparatus |
| CN102879261A (en) * | 2012-09-28 | 2013-01-16 | 北京理工大学 | Reluctance-type miniature Hopkinson tension and pressure integrated bar device |
| CN103134750A (en) * | 2013-02-01 | 2013-06-05 | 河海大学 | Steel bar drawing testing device suitable for Hopkinson pressure bar |
Non-Patent Citations (1)
| Title |
|---|
| 孙伟等: ""活性粉末混凝土冲击拉伸试验研究"", 《广州大学学报（自然科学版）》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106093194A (en) * | 2016-06-03 | 2016-11-09 | 河海大学 | The test device of the lower quasi-brittle material stress wave attentuation rule of blast and amount levy method |
| CN106093194B (en) * | 2016-06-03 | 2019-07-12 | 河海大学 | The test device and amount sign method for lower quasi-brittle material stress wave attentuation rule of exploding |
| CN105928808A (en) * | 2016-07-01 | 2016-09-07 | 河海大学 | Measuring and determining method for spall strength of quasi-brittle material at high strain rate |
| CN107228802A (en) * | 2017-06-15 | 2017-10-03 | 东北大学 | A kind of SHPB devices and its application method for obtaining half-sine wave under different loading speeds |
| CN116380619A (en) * | 2022-12-26 | 2023-07-04 | 中国人民解放军军事科学院国防工程研究院工程防护研究所 | Method for determining residual spalling strength of steel fiber concrete under repeated impact load |
| CN116380619B (en) * | 2022-12-26 | 2024-02-27 | 中国人民解放军军事科学院国防工程研究院工程防护研究所 | Method for determining residual spalling strength of steel fiber concrete under repeated impact load |
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Effective date of registration: 20210422 Address after: 710000, No. eight, No. 18 East Road, Yanta District, Shaanxi, Xi'an Patentee after: POWERCHINA NORTHWEST ENGINEERING Co.,Ltd. Patentee after: HOHAI University Address before: 211100 Jiangsu City, Jiangning Province Development Zone, West Road, No. 8 Buddha Patentee before: HOHAI University |
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Inventor after: Yang Dangfeng Inventor after: Deng Hengxin Inventor after: Su Feng Inventor after: Liu Xiaodong Inventor after: Huang Yong Inventor after: Chen Xudong Inventor after: Chen Chen Inventor after: Shao Yu Inventor after: Xu Lingyu Inventor after: Sheng Ruqing Inventor before: Chen Xudong Inventor before: Chen Chen Inventor before: Shao Yu Inventor before: Xu Lingyu Inventor before: Sheng Ruqing Inventor before: Deng Hengxin |
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