CN107978202A - Multifunction experiment apparatus and experimental method - Google Patents

Abstract

The present invention is applicable to the field of material mechanics experiments, and provides a multifunctional experimental device and an experimental method. The experimental device includes: a support frame, an experimental beam, a vertical movement assembly, a loading weight assembly and a dial indicator assembly. Through the above The experimental device can complete four experiments of material mechanics, that is, the force method solution statically indeterminate experiment, the beam bending deformation experiment, the reciprocal theorem experiment of work, and the superposition principle experiment, which can save teaching costs and save the space occupied by experimental equipment.

Description

Multifunctional experimental device and experimental method

technical field

The invention belongs to the field of material mechanics experiments and provides a multifunctional experimental device and an experimental method.

Background technique

Existing material mechanics force method to solve statically indeterminate experiment, beam bending deformation experiment, work reciprocity theorem experiment, and superposition principle experiment are all carried out through independent experimental devices. To complete the above four experiments, four experiments are required. Equipment, while occupying a large amount of space in the school, increases the financial expenditure of the school.

Contents of the invention

The embodiment of the present invention provides a multifunctional experimental device, which aims to provide a simple structure and multifunctional experimental device, which can realize the force method to solve the hyperstatic experiment, the bending deformation experiment of the beam, and the mutual equivalence of work on the same experimental device. Operation of theorem experiment and superposition principle experiment.

The present invention is achieved like this, a kind of multifunctional experiment device, described device comprises:

The supporting frame is composed of two parallel beams and two parallel longitudinal beams, and the top beam is provided with a first guide groove;

The experimental beam is set on the plane where the two beams are located, one end is vertically fixed to the first longitudinal beam, and the other end is a free end, and the resistance strain gauge is pasted on the experimental beam;

The vertical moving component includes: a vertical moving part arranged at the bottom of the free end of the experimental beam, and a connecting plate arranged between the vertical moving part and the second longitudinal beam, one side of the connecting plate is slidingly connected with the vertical moving part, The top of the vertical moving part is fixed with a force sensor, the bottom is provided with a rotating hand wheel, the other side of the connecting plate is fixedly connected with the second longitudinal beam, and the bottom of the connecting plate is provided with a bottom plate along the extending direction of the vertical moving part, the bottom plate and The rotating handwheel is threadedly connected, and the marking line and the scale matching the marking line are respectively engraved on the vertical plane of the vertical moving part and the connecting plate;

The loading weight assembly includes: two weight support rods for fixing the loading weight, and two weight support plates respectively arranged at the bottom of the two weight support rods. The weight support plates are all arranged parallel to the longitudinal beams. When no weight is loaded, the bottom of the weight support plate is just in contact with the top of the experimental beam, and the tops of the two weight support rods are slidably connected to the first guide groove on the top beam through the slider respectively, and the weight support rod and the slider The center hole is clearance fit;

The dial gauge assembly, the dial gauge fixing component is arranged between the experimental beam and the bottom cross beam, including: two dial gauges, the dial gauge support rod arranged between the two dial gauges and the experimental beam, in the percentage There is a second guide groove on the dial support rod, and the second guide groove and the dial indicator support rod are arranged parallel to the beam, and the two Us are sleeved on the side ends of the dial dial support rod and are slidably connected with the dial dial support rod. U-shaped guide sleeves, and two connecting measuring rods passing through the two U-shaped guide sleeves and the second guide groove respectively, one end of the two measuring rods is all fixed with a dial indicator, and the other end is in contact with the bottom of the experimental beam.

Further, the loading weight assembly includes: a bar-shaped groove arranged on one side of the first guide groove, the bar-shaped groove is arranged parallel to the beam, and the two screw rods are fixedly connected to the two sliders through the bar-shaped groove, and are matched with the two screw rods Two Screw Caps.

Further, the dial gauge assembly includes: two threaded through holes arranged on the two U guide sleeves, and two screws matched with the two threaded through holes.

Further, the vertical moving part is a dovetail slider, and the side wall of the connecting plate is provided with a dovetail chute matching with the dovetail slider.

The embodiment of the present invention provides a method for solving hyperstatically indeterminate experiments based on a multifunctional experimental device. The method includes the following steps:

S11. Adjust the position of the vertical moving part in the vertical direction by rotating the handwheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block. At this time, the force sensor on the top of the vertical moving part and the experimental beam bottom contact;

S12. Fix a weight support rod at any position, and add weights to the weight support rod in the same amount step by step, step S13, step S14, and step S15 must be executed in sequence every time the weight is added;

S13, recording the reading N _1n of the force sensor;

S14. The vertical moving part is moved down by rotating the handwheel until the force sensor at the top of the vertical moving part is separated from the free end of the experimental beam, and the experimental beam becomes a statically determinate cantilever beam;

S15, the vertical moving part is moved up by rotating the hand wheel, and the marking line of the vertical moving part is aligned with the zero scale line on the connecting plate, and the reading _N of the force sensor is recorded at this time;

S16. Under the same load, calculate the relative error between the force sensor reading N _1n and the force sensor reading N _2n . In theory, under the same load, the force sensor reading N _1n is equal to the force sensor reading N _2n .

The beam bending deformation experimental method based on the multifunctional experimental device provided by the embodiment of the present invention, the method includes the following steps:

S21. Make the vertical moving part move down by turning the hand wheel, and move down to the bottom of the force sensor to complete the detachment from the test beam;

S22. Fix one of the weight support rods at position 1, fix the dial indicator at position 2, add equal amounts of weights to the weight support rod at position 1 step by step, and record the reading W _2n of the dial indicator;

S23. Measure the distance between the fixed point of the weight support rod and the fixed point of the dial gauge from the first longitudinal beam;

S24. Calculate the bending deformation W _n at the fixed position of the dial indicator based on the formula (1), the expression of the formula (1) is as follows:

E is the modulus of elasticity of the experimental beam, a is the distance between the fixed point of the weight support rod and the first longitudinal beam, x is the distance between the fixed point of the dial indicator and the first longitudinal beam, F is the load of the loaded weight, and I is Experimental beam section moment of inertia

S25. Calculate the relative error between the calculated value W _n of the bending deformation at the fixed position of the dial indicator and the reading value W _2n of the dial indicator.

The embodiment of the present invention provides an experimental method based on the multifunctional experimental device for the theorem of mutual equivalence, said method comprising the steps of:

S31. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block;

S32. Select two fixed points position 1 and position 2 on the experimental beam, fix the weight support rod at position 1, fix the dial indicator at position 2, and load the weight support rod at position 1 step by step in equal amounts For weights, record the load P ₁ at position 1 and the real number W ₂ of the dial indicator at position 2 in sequence. After the measurement is completed, remove the loaded weights on the weight support rod at position 1 in sequence;

S33. Fix the weight support rod at position 2, fix the dial indicator at position 1, load equal amounts of weights on the weight support rod step by step, and record the load P ₂ at position 2 and the percentage at position 1 in sequence Table real number W ₁ ;

S34. Verify whether the reciprocal theorem relationship P ₁ W ₂ =P ₂ W ₁ is established;

S35. Control the vertical moving part to move down by rotating the hand wheel until the force sensor is completely detached from the bottom of the test beam, and the test beam becomes a statically determinate cantilever beam. Steps S32, S33, and S34 are executed.

The superposition principle experimental method based on the multifunctional experimental device provided by the embodiment of the present invention, the method comprises the following steps:

S41. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block;

S42. Select three fixed points position 1, position 2 and position 3 on the experimental beam, fix the two weight support rods and the dial indicator at position 1 and position 2 respectively, fix the dial indicator at position 3, and set the resistance The strain gauge is connected to the strain gauge by the half-bridge method, and the weights are loaded on the weight support rod in equal amounts step by step, and the readings of the dial indicator W _12-n , the readings of the force sensor N _12-n , and the readings of the strain gauge are sequentially recorded. The reading is ε _12-n . After the measurement is completed, remove the weights loaded on the weight support rod at position 1 and the weight support rod at position 2 in sequence;

S43. Load equal amounts of weights step by step on the weight support rod at position 1, record the readings W _1n of the dial indicator, the readings N _1n of the force sensor, and the readings ε _1n of the strain gauge in sequence. The loaded weights on the weight support rod at one place are removed in sequence;

S44. Load equal amounts of weights step by step on the weight support rod at position 2, and sequentially record the readings W _2n of the dial indicator, the readings N _2n of the force sensor, and the readings ε _2n of the strain gauge;

S45, verify whether the formula (2) is established, the expression of the formula (2) is as follows:

S46. Control the vertical moving part to move down by rotating the hand wheel until the force sensor is completely detached from the bottom of the test beam, and the test beam becomes a statically definite cantilever beam. Steps S42, S43, S44 and S45 are executed.

Through the above-mentioned experimental device, four experiments of material mechanics can be completed, that is, the force method to solve the statically indeterminate experiment, the bending deformation experiment of the beam, the reciprocal theorem experiment of work, and the superposition principle experiment, which can save teaching costs and save the space occupied by experimental consumables .

Description of drawings

Fig. 1 is the structural representation of the multifunctional experiment device that the embodiment of the present invention provides;

FIG. 2 is a schematic diagram of an enlarged structure of a vertical movement assembly provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of an enlarged structure of a dial indicator assembly provided by an embodiment of the present invention;

Fig. 4 is a process diagram of the statically indeterminate experimental solution of the force method provided by the embodiment of the present invention.

11. Top beam, 12. First longitudinal beam, 13. Bottom beam, 14. Second longitudinal beam, 21. Experimental beam, 22. Resistance strain gauge, 31. Vertical moving part, 32. Connecting plate, 33. Force Sensor, 34. Rotating hand wheel, 35. Bottom plate, 41. Weight support rod, 42. Weight support plate, 43. Slider, 44. First guide groove slide, 45. Bar groove, 51. Percent indicator , 52. Dial indicator support rod, 53. Second guide groove, 54. U-shaped guide sleeve, 55. Measuring rod, 56. Screw.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

FIG. 1 is a schematic structural diagram of a multifunctional experimental device provided by an embodiment of the present invention. For convenience of description, only parts related to the embodiment of the present invention are shown.

The unit includes:

Support frame, this support frame is made up of two mutually parallel beams, and two mutually parallel longitudinal beams, and cross beam comprises top beam 11 and bottom beam 13, and longitudinal beam comprises first longitudinal beam 12 and second longitudinal beam 14, and top beam 11 There is a first guide 44 on it;

The experimental beam 21 is located on the plane where the two beams are located, and one end is vertically fixed to the first longitudinal beam 12, and the other end is a free end. The top of the experimental beam 21 is pasted with a resistance strain gauge 22;

The vertical moving assembly includes: a vertical moving part 31 located at the bottom of the free end of the test beam 21, and a connecting plate 32 between the vertical moving part 31 and the second longitudinal beam 14, one side of the connecting plate 32 is connected to the vertical The straight moving part 31 is slidingly connected, the top of the vertical moving part 31 is fixed with a force sensor 33, the bottom is provided with a rotating hand wheel 34, the other side of the connecting plate 32 is fixedly connected with the second longitudinal beam 14, and the bottom of the connecting plate 32 is The extension direction of the vertical moving part is provided with a bottom plate 35, and the bottom plate 35 is threadedly connected with the rotating hand wheel 34, and the vertical moving part 31 can be adjusted in the vertical position by rotating the hand wheel 34, and the vertical moving part 31 and the connection The vertical plane of the plate 32 is respectively engraved with a marking line and a scale matching the marking line. When the marking line of the vertical moving part 31 is aligned with the zero scale line on the connecting block 32, the force on the top of the vertical moving part 31 The sensor 33 is in contact with the bottom of the experimental beam 21;

The loading weight assembly includes: two weight support rods 41 for fixing the loading weight, and two weight support plates 42 respectively arranged at the bottom of the two weight support rods, and the weight support plates 42 are all parallel to the longitudinal beam Set, when no weight is loaded, the bottom of the weight support plate 42 just contacts the top of the test beam 21, and the tops of the two weight support rods 41 pass through the slide block 43 and the first guide groove slide 44 on the top beam 11 respectively. Dynamically connected, the center hole of the weight support rod 41 and the slider 43 is clearance fit;

Dial gauge assembly, this dial gauge fixing assembly is located between the experimental beam 21 and the bottom cross beam 13, comprises: two dial gauges 51, the dial gauge bracket that is located between two dial gauges 51 and the experimental beam 12 Rod 52 is provided with second guide groove 53 on dial indicator drag bar 52, and second guide groove 53 and dial indicator support rod 52 are all arranged parallel to the beam, and are sleeved on dial indicator support rod 52 side ends and Two U-shaped guide sleeves 54 that are slidably connected with the dial indicator support rod 52, and two connected measuring rods 55 that pass through the two U-shaped guide sleeves 54 and the second guide groove 53 respectively, and one end of the two measuring rods 55 is fixed to a percentage. Table 51, the other end is in contact with the bottom of the experimental beam 21.

In the embodiment of the present invention, the loading weight assembly 4 further includes: a bar-shaped groove 45 arranged on the side wall of the first guide groove 44, the bar-shaped groove 45 is arranged parallel to the beam, and passes through the bar-shaped groove 45 and the two sides. The slide block 43 is fixedly connected with two screw rods and two nuts matched with the two screw rods. When the nuts are pressed against the side wall of the strip groove, the weight support rod can be fixed at any position of the experimental beam.

In the embodiment of the present invention, the dial gauge assembly also includes: two threaded through holes arranged on the two U guide sleeves 54, and two screws 56 matched with the two threaded through holes, by rotating the screws 56 to realize the measurement rod in the experiment Fixation of any detection position of the beam.

Fig. 2 is an enlarged structural schematic diagram of the vertical movement assembly provided by the embodiment of the present invention, only showing the parts related to the embodiment of the present invention;

In this implementation, the vertical moving part adopts a dovetail slider, and the dovetail slider cooperates with the dovetail chute on the connecting side wall to realize the vertical movement. The scale connecting plate is connected and fixed with the U-shaped connecting member through the countersunk head screw. The U-shaped connecting member is clamped on the second longitudinal beam. The dovetail slider is placed in the dovetail groove of the connecting plate with scale. The block moves up and down, and the force is transmitted to the free end of the experimental beam through the force sensor, or the structure conversion between the statically indeterminate beam and the ultra-statically indeterminate beam is realized; when the dovetail slider moves down, the upper end of the force sensor is separated from the right end of the experimental beam , is a statically indeterminate beam; when the dovetail slider moves up so that the upper end of the force sensor touches the right end of the experimental beam, it is a statically indeterminate beam.

Fig. 3 is a schematic diagram of an enlarged structure of a dial indicator assembly provided by an embodiment of the present invention. For convenience of description, only parts related to the embodiment of the present invention are shown.

The installation and fixing method of the dial indicator is shown in Figure 3. There is a second guide groove on the dial indicator support rod, and the measuring rod of the dial indicator passes through the second guide groove and the guide sleeve and can be placed in the second guide groove. Move left and right, and fix the dial indicator by tightening the set screw on the sleeve.

Through the above-mentioned experimental device, four experiments of material mechanics can be completed, that is, the force method to solve the statically indeterminate experiment, the bending deformation experiment of the beam, the reciprocal theorem experiment of work, and the superposition principle experiment, which can save teaching costs and save the space occupied by experimental consumables .

In the embodiment of the present invention, the force method to solve the hyperstatic experiment needs to complete four processes (a), (b), (c) and (d) as shown in Figure 4, the basic method of the force method to solve the hyperstatic structure The idea is to transform the hyperstatically indeterminate problem into an equivalent statically indeterminate problem to solve. The solution process is to remove the "redundant constraint" at the support C and replace it with the restraint reaction force F _C , thus obtaining the hyperstatically indeterminate structure The basic system solved by the force method, when the vertical displacement Δ _Cy at the support C = 0, the basic system is the equivalent statically indeterminate problem of the original hyperstatically indeterminate problem.

Based on the above-mentioned multifunctional experimental device, the force method solution to the hyperstatic experimental method comprises the following steps:

S11. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block;

S12. Fix a weight support rod at any position, and add weights to the weight support rod in equal amounts step by step, and perform the following steps S13, S14 and S15 in sequence every time a weight is added;

S13, recording the reading N _1n of the force sensor;

S14. The vertical moving part is moved down by rotating the handwheel until the force sensor at the top of the vertical moving part is separated from the free end of the experimental beam, and the experimental beam becomes a statically determinate cantilever beam;

S15, the vertical moving part is moved up by rotating the hand wheel, and the marking line of the vertical moving part is aligned with the zero scale line on the connecting plate, and the reading _N of the force sensor is recorded at this time;

S16. Calculate the relative error of the readings (N _1n and N _2n ) of the force sensor under the same load. In theory, the reading N _1n of the force sensor is equal to the reading N _2n of the force sensor under the same load.

The bending deformation experimental method of the beam based on the above-mentioned multifunctional experimental device comprises the following steps:

S21. Make the vertical moving part move down by turning the hand wheel, and move down to the bottom of the force sensor to complete the detachment from the test beam;

S22. Fix one of the weight support rods at position 1, fix the dial gauge at position 2, add equal amounts of weights to the weight support rod step by step, and record the reading W _2n of the dial gauge;

S23. Measure the distance between the fixed point of the weight support rod and the fixed point of the dial gauge from the first longitudinal beam;

S24. Calculate the bending deformation W _n at the fixed position of the dial indicator based on the formula (1), the expression of the formula (1) is as follows:

E is the modulus of elasticity of the experimental beam, a is the distance between the fixed point of the weight support rod and the first longitudinal beam, x is the distance between the fixed point of the dial indicator and the first longitudinal beam, F is the load of the loaded weight, and I is Moment of inertia of the experimental beam section;

S25. Calculate the relative error between the calculated value W _n of the bending deformation at the fixed position of the dial indicator and the reading value W _2n of the dial indicator.

The reciprocal theorem experimental method based on the work of the above-mentioned multifunctional experimental device comprises the steps:

S31. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block;

S32. Select two fixed points position 1 and position 2 on the experimental beam, fix the weight support rod at position 1, fix the dial indicator at position 2, load equal amounts of weights on the weight support rod step by step, and then Record the load P ₁ at position 1 and the real number W ₂ of the dial indicator at position 2. After the measurement is completed, remove the weights loaded on the weight support rod at position 1 in sequence;

S33. Fix the weight support rod at position 2, fix the dial indicator at position 1, load equal amounts of weights on the weight support rod step by step, and record the load P ₂ at position 2 and the percentage at position 1 in sequence Table real number W ₁ ;

S34. Verify whether the reciprocal theorem relationship P ₁ W ₂ =P ₂ W ₁ is established;

S35. Control the vertical moving part to move down by rotating the hand wheel until the force sensor is completely detached from the bottom of the test beam, and the test beam becomes a statically determinate cantilever beam. Steps S32, S33, and S34 are executed.

The superposition principle experimental method based on the above-mentioned multifunctional experimental device comprises the following steps:

S41. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block;

S42. Select three fixed points position 1, position 2 and position 3 on the experimental beam, fix the two weight support rods and the dial indicator at position 1 and position 2 respectively, fix the dial indicator at position 3, and set the resistance The strain gauge is connected to the strain gauge by the half-bridge method, and the weights are loaded on the weight support rod in equal amounts step by step, and the readings of the dial indicator W _12-n , the readings of the force sensor N _12-n , and the readings of the strain gauge are sequentially recorded. The reading is ε _12-n . After the measurement is completed, remove the loaded weights on the weight support rod at position 1 and the weight support rod at position 2 in sequence;

S43. Load equal amounts of weights step by step on the weight support rod at position 1, record the readings W _1n of the dial indicator, the readings N _1n of the force sensor, and the readings ε _1n of the strain gauge in sequence. The weights loaded on the weight support rod at one place are removed in sequence;

S44. Load equal amounts of weights step by step on the weight support rod at position 2, and sequentially record the readings W _2n of the dial indicator, the readings N _2n of the force sensor, and the readings ε _2n of the strain gauge;

S45, verify whether the formula (2) is established, the expression of the formula (2) is as follows:

S46. Control the vertical moving part to move down by rotating the hand wheel until the force sensor is completely detached from the bottom of the test beam, and the test beam becomes a statically definite cantilever beam. Steps S42, S43, S44 and S45 are executed.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (8)

1. A multifunctional experimental device, characterized in that the device comprises: The supporting frame is composed of two parallel beams and two parallel longitudinal beams, the beams include a top beam and a bottom beam, the longitudinal beams include a first longitudinal beam and a second longitudinal beam, and the top beam is provided with a first guide groove; The experimental beam is set on the plane where the two beams are located, one end is vertically fixed to the first longitudinal beam, and the other end is a free end, and the resistance strain gauge is pasted on the experimental beam; The vertical moving assembly includes: a vertical moving part arranged at the bottom of the free end of the experimental beam, and a connecting plate arranged between the vertical moving part and the second longitudinal beam, one side of the connecting plate is slidingly connected with the vertical moving part, The top of the vertical moving part is fixed with a force sensor, the bottom is provided with a rotating hand wheel, the other side of the connecting plate is fixedly connected with the second longitudinal beam, and the bottom of the connecting plate is provided with a bottom plate along the extending direction of the vertical moving part, the bottom plate and The rotating handwheel is threadedly connected, and the marking line and the scale matching the marking line are respectively engraved on the vertical plane of the vertical moving part and the connecting plate. When the marking line is aligned with the zero scale line on the connecting block, it will move vertically. The force transducer at the top of the piece is in contact with the bottom of the experimental beam; The loading weight assembly includes: two weight support rods for fixing the loading weight, and two weight support plates respectively arranged at the bottom of the two weight support rods. The weight support plates are all arranged parallel to the longitudinal beams. When no weight is loaded, the bottom of the weight support plate is just in contact with the top of the experimental beam, and the tops of the two weight support rods are slidably connected to the first guide groove on the top beam through the slider respectively, and the weight support rod and the slider The center hole is clearance fit; The dial indicator assembly is arranged between the experimental beam and the bottom beam, including: two dial indicators, a dial indicator support rod arranged between the two dial indicators and the experimental beam, and a dial indicator support rod is provided on the dial indicator support rod. The second guide groove, the second guide groove and the dial indicator support rod are all arranged parallel to the cross beam, and the two U-shaped guide sleeves that are sleeved on the side ends of the dial indicator support rod and are slidably connected with the dial indicator support rod, and respectively Two connecting measuring rods passing through the two U-shaped guide sleeves and the second guide groove, one end of the two measuring rods is fixed with a dial indicator, and the other end is in contact with the bottom of the experimental beam. 2. The multifunctional experimental device as claimed in claim 1, wherein the loading weight assembly comprises: a bar-shaped groove arranged on one side of the first guide groove, the bar-shaped groove is arranged with parallel beams, and passes through the bar-shaped groove Two screw rods are fixedly connected with the two slide blocks, and two nuts matched with the two screw rods. 3. The multifunctional experimental device according to claim 1, wherein the dial indicator assembly comprises: two threaded through holes arranged on the two U guide sleeves, and two screws matched with the two threaded through holes. 4. The multifunctional experimental device according to claim 1, wherein the vertical moving part is a dovetail slider, and the side wall of the connecting plate is provided with a dovetail chute matched with the dovetail slider. 5. based on the force method solution hyperstatic experimental method of the described multifunctional experimental device of claim 1-4 arbitrary claim, it is characterized in that, described method comprises the steps: S11. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block; S12. Fix a weight support rod at any position, and add weights to the weight support rod in the same amount step by step, step S13, step S14, and step S15 must be executed in sequence every time the weight is added; S13, recording the reading N _1n of the force sensor; S14. The vertical moving part is moved down by rotating the handwheel until the force sensor at the top of the vertical moving part is separated from the free end of the experimental beam, and the experimental beam becomes a statically determinate cantilever beam; S15, the vertical moving part is moved up by rotating the hand wheel, and the marking line of the vertical moving part is aligned with the zero scale line on the connecting plate, and the reading _N of the force sensor is recorded at this time; S16. Under the same load, calculate the relative error between the force sensor reading N _1n and the force sensor reading N _2n . In theory, under the same load, the force sensor reading N _1n is equal to the force sensor reading N _2n . 6. based on the beam bending deformation experimental method of the described multifunctional experimental device of claim 1-4 arbitrary claim, it is characterized in that, described method comprises the steps: S21. Make the vertical moving part move down by turning the hand wheel, and move down to the bottom of the force sensor to complete the detachment from the test beam; S22. Fix one of the weight support rods at position 1, fix the dial indicator at position 2, add equal amounts of weights to the weight support rod at position 1 step by step, and record the reading W _2n of the dial indicator; S23. Measure the distance between the fixed point of the weight support rod and the fixed point of the dial gauge from the first longitudinal beam; S24. Calculate the bending deformation W _n at the fixed position of the dial indicator based on the formula (1), the expression of the formula (1) is as follows: <mrow><mi>W</mi><mo>=</mo><mo>{</mo><mtable><mtr><mtd><mrow><mo>-</mo><mfrac><mrow><msup><mi>Fx</mi><mn>2</mn></msup></mrow><mrow><mn>6</mn><mi>E</mi><mi>I</mi></mrow></mfrac><mrow><mo>(</mo><mn>3</mn><mi>a</mi><mo>-</mo><mi>x</mi><mo>)</mo></mrow><mrow><mo>(</mo><mn>0</mn><mo>&amp;le;</mo><mi>x</mi><mo>&amp;le;</mo><mi>a</mi><mo>)</mo></mrow></mrow></mtd></mtr><mtr><mtd><mrow><mo>-</mo><mfrac><mrow><msup><mi>Fa</mi><mn>2</mn></msup></mrow><mrow><mn>6</mn><mi>E</mi><mi>I</mi></mrow></mfrac><mrow><mo>(</mo><mn>3</mn><mi>x</mi><mo>-</mo><mi>a</mi><mo>)</mo></mrow><mrow><mo>(</mo><mi>a</mi><mo>&amp;le;</mo><mi>x</mi><mo>&amp;le;</mo><mi>l</mi><mo>)</mo></mrow></mrow></mtd></mtr></mtable><mo>-</mo><mo>-</mo><mo>-</mo><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mrow> E is the modulus of elasticity of the experimental beam, a is the distance between the fixed point of the weight support rod and the first longitudinal beam, x is the distance between the fixed point of the dial indicator and the first longitudinal beam, F is the load of the loaded weight, and I is The moment of inertia of the experimental beam section. S25. Calculate the relative error between the calculated value W _n of the bending deformation at the fixed position of the dial indicator and the reading value W _2n of the dial indicator. 7. based on claim 1-4 arbitrary claim described multi-functional experimental device theorem experimental method of reciprocity of work, it is characterized in that, described method comprises the steps: S31. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block; S32. Select two fixed points position 1 and position 2 on the experimental beam, fix the weight support rod at position 1, fix the dial indicator at position 2, and load the weight support rod at position 1 step by step in equal amounts For weights, record the load P ₁ at position 1 and the dial indicator reading W ₂ at position 2 in sequence. After the measurement is completed, remove the weights loaded on the weight support rod at position 1 in sequence; S33. Fix the weight support rod at position 2, fix the dial indicator at position 1, load equal amounts of weights step by step on the weight support rod at position 2, and record the load P ₂ at position 2 and position 1 in sequence The dial gauge real number W ₁ at the place; S34. Verify whether the reciprocal theorem relationship P ₁ W ₂ =P ₂ W ₁ is established; S35. Control the vertical moving part to move down by rotating the hand wheel until the force sensor is completely detached from the bottom of the test beam, and the test beam becomes a statically determinate cantilever beam. Steps S32, S33, and S34 are executed. 8. based on the superposition principle experimental method of the described multifunctional experimental device of claim 1-4 arbitrary claim, it is characterized in that, described method comprises the steps: S41. Adjust the position of the vertical moving part in the vertical direction by rotating the hand wheel, so that the marking line of the vertical moving part is aligned with the zero scale line on the connecting block; S42. Select the three fixed points position 1, position 2 and position 3 on the experimental beam, fix the two weight support rods at position 1 and position 2 respectively, fix the dial indicator at position 3, and use the half bridge for the resistance strain gauge Connect the strain gauge with the method, load the weights on the weight support rods at positions 1 and 2 in equal amounts step by step, and record the readings W _12-n of the dial indicator, the readings N _12-n of the force sensor, and the strain The reading of the instrument is ε _12-n . After the measurement, remove the weights loaded on the weight support rod at position 1 and the weight support rod at position 2 in sequence; S43. Load equal amounts of weights step by step on the weight support rod at position 1, record the readings W _1n of the dial indicator, the readings N _1n of the force sensor, and the readings ε _1n of the strain gauge in sequence. The weights loaded on the weight support rod at one place are removed in sequence; S44. Load equal amounts of weights step by step on the weight support rod at position 2, record the readings W _2n of the dial indicator, the readings N _2n of the force sensor, and the readings ε _2n of the strain gauge in sequence. The weights loaded on the two weight support rods are removed in sequence; S45, verify whether the formula (2) is established, the expression of the formula (2) is as follows: <mfenced open = "{" close = ""><mtable><mtr><mtd><msub><mi>N</mi><mrow><mn>12</mn><mo>-</mo><mi>n</mi></mrow></msub><mo>=</mo><msub><mi>N</mi><mrow><mn>1</mn><mi>n</mi></mrow></msub><mo>+</mo><msub><mi>N</mi><mrow><mn>2</mn><mi>n</mi></mrow></msub></mtd></mtr><mtr><mtd><mrow><msub><mi>E&amp;epsiv;</mi><mrow><mn>12</mn><mo>-</mo><mi>n</mi></mrow></msub><mo>=</mo><msub><mi>E&amp;epsiv;</mi><mrow><mn>1</mn><mi>n</mi></mrow></msub><mo>+</mo><msub><mi>E&amp;epsiv;</mi><mrow><mn>2</mn><mi>n</mi></mrow></msub></mrow></mtd></mtr><mtr><mtd><mrow><msub><mi>W</mi><mrow><mn>12</mn><mo>-</mo><mi>n</mi></mrow></msub><mo>=</mo><msub><mi>W</mi><mrow><mn>1</mn><mi>n</mi></mrow></msub><mo>+</mo><msub><mi>W</mi><mrow><mn>2</mn><mi>n</mi></mrow></msub></mrow></mtd></mtr></mtable></mfenced> S46. Control the vertical moving part to move down by rotating the hand wheel until the force sensor is completely detached from the bottom of the test beam, and the test beam becomes a statically definite cantilever beam. Steps S42, S43, S44 and S45 are executed.