Background technology:
Concrete in uniaxial tension and compression constitutive relation is the basis of xoncrete structure research, comprising as important mechanical performance indexs such as intensity, ultimate deformation, elastic modulus, it is an important evidence of concrete failure mechanism of research and strength theory, is again accurately to analyze the indispensable theoretical foundation of xoncrete structure performance.
The research great majority of concrete material performance concentrate on its static properties, but in actual environment, industrial, civilian and military buildings is not only bearing the effect of static load, also inevitably suffer from the effect of dynamic loads such as earthquake, impact, blast, the attack of train vibration enemy bullet, though, these loads are not all to act on structurally all the time, but because its unpredictability reaches structural damage, make them often become the key factor of control structure design.And the dynamic property of present concrete material is the weak link in large-sized concrete structural design and the quake-resistant safety evaluation, and especially in recent years, building is taken place by the accident of the attack of terrorism repeatedly, and the importance of concrete Research on Dynamic Characteristic more looms large.
Relevant concrete dynamic perfromance, strictness is concrete rate of strain correlation properties in fact, find for the first time that from Abrams in 1917 there is rate susceptibility in the dynamic compressive strength of concrete so far, people to the dynamic mechanical of concrete under different strain rate promptly the relevant mechanical property of rate carried out extensive studies.But the power load test is more than static(al) load test complexity, mostly present experimental study is to carry out under the condition of no initial static load, and mostly actual xoncrete structure is to bear dynamic loads on the basis of static load again bearing, trace it to its cause, mainly be because there is not suitable device to realize, therefore, be badly in need of a kind of device of exploitation and can under certain load, record the concrete in uniaxial tension and compression ess-strain full curve under the different strain rate.
The utility model content:
The purpose of this utility model is to carry out comprehensive and systematic test by test unit, and a kind of concrete stress strain full curve test unit of controlled loading speed is provided.
The utility model adopts following technical scheme:
A kind of concrete stress strain full curve test unit of controlled loading speed, comprise base, pillar, main actuator, from actuator, workbench, it is characterized in that: on the described base pillar is housed, the other end of this pillar is connected with entablature, be set with workbench on the described pillar, the above and below of described workbench is equipped with load plate and following load plate respectively, both are connected by the guide rod that passes workbench for this, the other end that should go up load plate is connected with described entablature by main actuator, the other end of this time load plate be connected from actuator, this workbench is equipped with it and draws, the pulling force sensor assembly and the pressure transducer assembly that connect when pressing test.
The utility model compared with prior art has following advantage:
1. owing to the load of main actuator in process of the test remains unchanged, so the power that acts on load plate and the entablature is constant, and then can avoid the interference of the variation of test unit distortion to curve descending branch measurement stability, obtain complete ess-strain full curve;
2. by control from the velocity of displacement of actuator, can control the rate of strain of test specimen, record that concrete in uniaxial under the different strain rate is drawn, the compressive stress strain full curve;
3. can make the distortion of test specimen by the rigidity of adjusting guide rod and, reduce the variation (ratio of test specimen maximum instantaneous strain rate and average strain rate is less than 2.0) of strain rate in the process of the test, reach at the uniform velocity loading substantially from the sexual intercourse of actuator displacement retention wire.
Embodiment:
Below in conjunction with drawings and Examples in detail the utility model is described in detail;
Embodiment 1:
A kind of concrete stress strain full curve test unit of controlled loading speed, referring to accompanying drawing 1, by base 1, pillar 2, down load plate 3, nut 4, workbench 5, nut 6, go up load plate 7, main actuator 8, entablature 9, on connect bearing 10, pressure transducer 11, go up ball hinged support 12, pulling force length travel sensor 13, pulling force transversal displacement sensor 14, down ball hinged support 16, down connection bearing 17, guide rod 18, form from actuator 19.
Wherein pressure transducer 11, pressure length travel sensor 13, pressure transversal displacement sensor 14 constitute the pressure transducer assembly of present embodiment.
Pillar 2 is housed on the base 1, the other end of pillar 2 is connected with entablature 9,2 are set with workbench 5 on the pillar, on the workbench 5, following two ends are affixed with pillar 2 lockings by nut 4 and nut 6 respectively, the above and below of workbench 5 is equipped with load plate 7 and following load plate 3 respectively, both are connected last load plate 7 and following load plate 3 by the guide rod 18 that is contained on the workbench 5, the other end of last load plate 7 is connected with entablature 9 by main actuator 8, the other end of following load plate 3 be connected from actuator 19, workbench 5 is equipped with the pressure transducer assembly that connects when doing the uniaxial compression test, pressure transducer assembly is by pressure transducer 11, pressure length travel sensor 13, pressure transversal displacement sensor 14 is formed, one end of pressure transducer 11 is connected with last load plate 7 by last connection bearing 10, its other end is connected with test specimen 15 by last ball hinged support 12, the other end of test specimen 15 successively by following ball hinged support 16 with under be connected bearing 17 and be connected with workbench 5, pressure length travel sensor 13 and pressure transversal displacement sensor 14 are housed on the test specimen 15.
Adopt electro-hydraulic control from actuator 19, test specimen 15 is placed between load plate 7 and the workbench 5, the speed that load plate 3 moves up under the control, thereby realize the uniaxial compression stress-strain diagram speed of control test specimen 15, when the test specimen to different length carries out the uniaxial compression test, can regulate the nut 4 and the relation of the fixed position between nut 6 and the pillar 2 at workbench 5 two ends.
Embodiment 2:
A kind of concrete stress strain full curve test unit of controlled loading speed, referring to accompanying drawing 2, by base 1, pillar 2, down load plate 3, nut 4, workbench 5, nut 6, go up load plate 7, main actuator 8, entablature 9, on connect bearing 10, pulling force sensor 11, go up ball hinged support 12, pulling force length travel sensor 13, pulling force transversal displacement sensor 14, down ball hinged support 16, down connection bearing 17, guide rod 18, form from actuator 19.
Wherein pulling force sensor 11, pulling force length travel sensor 13, pulling force transversal displacement sensor 14 constitute the pulling force sensor assembly of present embodiment.
Pillar 2 is housed on the base 1, the other end of pillar 2 is connected with entablature 9,2 are set with workbench 5 on the pillar, on the workbench 5, following two ends are affixed with pillar 2 lockings by nut 4 and nut 6 respectively, the above and below of workbench 5 is equipped with load plate 7 and following load plate 3 respectively, both are connected last load plate 7 and following load plate 3 by the guide rod 18 that is contained on the workbench 5, the other end of last load plate 7 is connected with entablature 9 by main actuator 8, the other end of following load plate 3 be connected from actuator 19, workbench 5 is equipped with the pulling force sensor assembly that connects when doing the test of single shaft tension, the pulling force sensor assembly is by pulling force sensor 11, pulling force length travel sensor 13, pulling force transversal displacement sensor 14 is formed, one end of pulling force sensor 11 is connected with workbench 5 by last connection bearing 10, its other end is connected with test specimen 15 by last ball hinged support 12, the other end of test specimen 15 successively by following ball hinged support 16 with under be connected bearing 17 and be connected with following load plate 3, pulling force length travel sensor 13 and pulling force transversal displacement sensor 14 are housed on the test specimen 15.
Adopt electro-hydraulic control from actuator 19, test specimen 15 is placed between workbench 5 and the following load plate 3, the speed that load plate 3 moves down under the control, thereby realize the single shaft tension stress-strain diagram speed of control test specimen 15, carry out the single shaft tension at the test specimen to different length and draw when test, nut 4 and the fixed position between nut 6 and the pillar 2 that can regulate workbench 5 two ends concern.