Circular-hole internal-wall hoop strain meter
Technical field
The present invention relates to rock deformation to measure, specifically refer to a kind of circular-hole internal-wall hoop strain meter.
Background technology
Along with the complexity of engineering construction continues to increase, in order to understand the mechanical property of Test in Situ better, need to carry out indoor mechanical test research to obtain intensity, the deformation and failure form of rock under complex stress effect to rock.The deformation failure because of rock is avoided to cause great engineering accident.
In engineering rock mass digging in-situ process, the stress state of rock mass inside is very complicated, shows as: in the constant situation in principal axis of stress direction, in principle stress size variation, the constant situation of principle stress size, principal axis of stress rotation, principal axis of stress direction rotate and principle stress size variation.Consider from macroscopic perspective, the change of above-mentioned stress state can cause rock mass to produce plastic yield, and elastic parameter and intensive parameter change; Consider from microcosmic angle, there are microfissure generation, through and expansion in rock mass inside.
At present, according to the loading characteristic of hollow cylinder sample, the hollow cylinder torsional shear instrument being applicable to soil sample and rock sample has been developed in Geotechnical Engineering field, can realize the stress path of the complexity such as principal axis of stress rotation.For rock hollow cylinder torsional shear instrument, strain measurement mainly adopts the mode at rock sample surface mount foil gauge at present, mainly there is following shortcoming in this kind of mode: 1) processes in rock sample process, the inwall of endoporus is rough, have brill line, foil gauge well can not be fitted with rock sample inwall; 2) the rock sample size for testing is less, and the work space pasting foil gauge in rock sample endoporus is little, is difficult to the paste position of controlled strain sheet, causes the strain recorded to produce error; 3) foil gauge is very fragile, fragile in later stage rock sample preparation process, and once be damaged, just can only abandon the data acquisition of this position, causes the data obtained imperfect; 4) data that foil gauge records can only reflect the distortion of sticking area local, have limitation.
Strain gauge method precision and reliability are not high, troublesome poeration, cause Test Data Collecting limited, affect the analysis of test findings.
Summary of the invention
Object of the present invention will provide a kind of circular-hole internal-wall hoop strain meter exactly, by the firm ring of fitting with circular-hole internal-wall by the displacement transfer of circular-hole internal-wall on the screw of the first steel disc, thus make the termination of screw apply pressure to one end of the second steel disc, because the other end of the second steel disc is fixed, second steel disc is deformed, the distortion of circular-hole internal-wall can be realized like this to be amplified to exponentially on the position at resistor disc place.
For achieving the above object, a kind of circular-hole internal-wall hoop strain meter designed by the present invention, for being placed in circular hole the distortion of measuring circular-hole internal-wall, it comprises firm ring, described firm ring offers an opening, be provided with the first support be arranged in parallel and the second support in described firm ring, one end of described first support and the second support is separately fixed at opening part, and described first support, the second support and firm ring are structure as a whole; Also comprise the first steel disc and strain gauge transducer, described strain gauge transducer comprises the second steel disc and resistor disc, and described second steel disc offers groove, and described resistor disc is attached to the bottom of groove, and the cable that resistor disc connects is drawn in circular hole; One end of described first steel disc is fixedly connected with the other end of the first support, the other end of described first steel disc is provided with the screw running through the first steel disc, conflict in the termination of described screw and one end of the second steel disc, the other end of described second steel disc is fixed on the other end of the second support, and described first steel disc and the second steel disc are horizontally disposed.
Preferably, described resistor disc near the other end of the second steel disc, away from one end of the second steel disc.
Further, one end of described first steel disc is fixedly connected with by the other end of bearing pin with the first support, and the other end of described second steel disc is fixedly connected with by the other end of bearing pin with the second support.
Again further, described first support is concordant with the two ends of the second support.
Further, the other end of described first steel disc is concordant with one end of the second steel disc.
The invention has the advantages that:
One, the present invention by the firm ring of fitting with circular-hole internal-wall by the displacement transfer of circular-hole internal-wall on the screw of the first steel disc, thus make the termination of screw apply pressure to one end of the second steel disc, because the other end of the second steel disc is fixed, second steel disc is deformed, the distortion of circular-hole internal-wall can be realized like this to be amplified to exponentially on the position at resistor disc place.
Its two, the second steel disc of the present invention is less than steel plate thickness corresponding to other position at the steel plate thickness that resistor disc position is corresponding, and this makes the second steel disc deform mainly to concentrate on steel disc position corresponding to resistor disc, make whole strainometer highly sensitive.
Its three, the present invention is reasonable in design, and structure is simple, and highly sensitive, good stability, is applicable to the strain measurement of endoporus.
Accompanying drawing explanation
Fig. 1 is a kind of structural representation of circular-hole internal-wall hoop strain meter;
Fig. 2 is the diagrammatic cross-section of Fig. 1 along A-A direction;
Fig. 3 is the structural representation in the firm ring of the present invention.
In figure: just ring 1; Opening 1.1; First support 2 (wherein: the first bearing pin 2.1); Second support 3 (wherein: the second bearing pin 3.1); First steel disc 4; Screw 4.1; Strain gauge transducer 5 (wherein: the second steel disc 5.1, resistor disc 5.2, groove 5.11); Cable 6.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail, but this embodiment should not be construed limitation of the present invention.
A kind of circular-hole internal-wall hoop strain meter as depicted in figs. 1 and 2, for being placed in circular hole the distortion of measuring circular-hole internal-wall, it comprises firm ring 1, firm ring 1 offers an opening 1.1, the first support 2 and the second support 3 be arranged in parallel is provided with in firm ring 1, one end of first support 2 and the second support 3 is separately fixed at opening 1.1 place, and the first support 2, second support 3 is structure as a whole with firm ring 1.
This device also comprises the first steel disc 4 and strain gauge transducer 5.Strain gauge transducer 5 comprises the second steel disc 5.1 and resistor disc 5.2, second steel disc 5.1 offers groove 5.11, resistor disc 5.2 is attached to the bottom of groove 5.11, the cable 6 that resistor disc 5.11 connects is drawn in circular hole, wherein resistor disc 5.2 is near the other end of the second steel disc 5.1, away from one end of the second steel disc 5.1.
As shown in Figure 3, one end of first steel disc 4 is fixedly connected with by the other end of the first bearing pin 2.1 with the first support 2, the other end of the first steel disc 4 is provided with the screw 4.1 running through the first steel disc 4, conflict in the termination of screw 4.1 and one end of the second steel disc 5.1, the other end of the second steel disc 5.1 is fixedly connected with by the other end of the second bearing pin 3.1 with the second support 3, and the first steel disc 4 and the second steel disc 5.1 are in horizontally disposed.Wherein, the first support 2 is concordant with the two ends of the second support 3; The other end of the first steel disc 4 is concordant with one end of the second steel disc 5.1.
When the present invention works, circular-hole internal-wall hoop strain meter is positioned in circular hole, the firm ring 1 of fitting with circular-hole internal-wall by the displacement transfer of circular-hole internal-wall on the screw 4.1 of the first steel disc 4, thus make the termination of screw 4.1 apply pressure to one end of the second steel disc 5.1, because the other end of the second steel disc 5.1 is fixed, second steel disc 5.1 is deformed, the distortion of circular-hole internal-wall can be realized like this to be amplified to exponentially on the position at resistor disc 5.2 place.
The content be not described in detail in this instructions, belongs to the known prior art of those skilled in the art.