RC beam damage model based on multi-gradient bending shear bearing capacity control
Through the RC beam damage model controlled by multi-gradient curved shear bearing capacity, combined with polystyrene foam plate and loading test, the problem of inaccurate damage assessment in the traditional model is solved, and the precise simulation of the damage state of RC beams and the intuitive reflection of the bearing capacity degradation process is achieved. It is suitable for a variety of RC beam structures.
Patent Information
- Application Number
- CN202422544827.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-10-22
AI Technical Summary
The traditional RC beam damage model ignores the multi-gradient impact of damage on the bearing capacity of the curved shear, and it is difficult to accurately reflect the damage and bearing capacity degradation process of the RC beam under actual load.
The RC beam damage model controlled by multi-gradient curved shear bearing capacity is adopted. By combining the first steel cage, the second steel cage, the concrete peeling damage structure and the crack damage structure, the polystyrene foam board is used to simulate different damage states, and the crack damage is controlled in combination with four-point loading tests to accurately simulate the mechanical behavior of the RC beam.
It improves the accuracy of damage assessment, can reflect the degradation process of bearing capacity more intuitively, provides a reliable basis for structural design and evaluation, and is suitable for RC beams of different types and sizes.
Smart Images
Figure CN223244229U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an RC beam damage model, in particular to an RC beam damage model based on multi-gradient bending and shear bearing capacity control. Background Art
[0002] RC beams are one of the most widely used components in building structures. Their damage models are of great significance for evaluating the seismic performance of structures and predicting the damage evolution process of structures.
[0003] Traditional damage models often use a single damage metric to describe the damage state of RC beams, ignoring the multi-gradient effects of damage on flexural and shear capacity. This makes it difficult to accurately reflect the damage and capacity degradation process of RC beams under actual loads. Therefore, a new damage model is needed that can comprehensively consider the impact of multiple gradients of flexural and shear capacity, thereby improving the accuracy and reliability of damage assessment. Utility Model Content
[0004] The main purpose of the present disclosure is to provide a RC beam damage model based on multi-gradient bending-shear bearing capacity control to effectively solve the problems raised by the inventor in the above background technology.
[0005] In order to achieve the above purpose, the technical solution adopted by the present utility model is as follows:
[0006] A RC beam damage model based on multi-gradient bending-shear bearing capacity control includes an RC beam damage model with concrete spalling, an RC beam damage model with cracks and mixed soil spalling, and an RC beam damage model with cracks. Each model is composed of a first steel cage, a second steel cage, mixed soil, a crack damage structure, and a concrete spalling damage structure. The concrete spalling damage structure is laid out using polystyrene foam boards, and the polystyrene foam boards are divided into a first foam board, a second foam board, a third foam board, and a fourth foam board. Each model is divided into RC beam damage model one, RC beam damage model two, RC beam damage model three, RC beam damage model four, RC beam damage model five, RC beam damage model six, RC beam damage model seven, RC beam damage model eight, and RC beam damage model nine.
[0007] Preferably, the concrete spalling damage structure of the RC beam damage model 1 is rectangular in shape and is located in the curved section of the RC beam, thereby controlling the degradation of the flexural bearing capacity of the RC beam.
[0008] Preferably, the concrete spalling damage structure of the second RC beam damage model is in the shape of a parallelogram and is located in the curved section of the RC beam.
[0009] Preferably, the concrete spalling damage structure of the RC beam damage model 5 is rectangular in shape and is located in the curved section of the RC beam, and a crack damage structure is provided on the RC beam damage model 5.
[0010] Preferably, the RC beam damage model 8 is provided with a crack damage structure.
[0011] Preferably, the concrete spalling damage structure of the RC beam damage model 3 is rectangular in shape and is located in the shear section of the RC beam, thereby controlling the degradation of the shear bearing capacity of the RC beam.
[0012] Preferably, the shape of the concrete spalling damage structure of the RC beam damage model 4 is a parallelogram.
[0013] Preferably, the concrete spalling damage structure of the RC beam damage model six is rectangular in shape and is located in the shear section of the RC beam, and a crack damage structure is provided on the RC beam damage model six.
[0014] Preferably, the concrete spalling damage structure of the RC beam damage model seven is in the shape of a parallelogram, and a crack damage structure is provided on the RC beam damage model seven.
[0015] Preferably, the RC beam damage model 9 is provided with a crack damage structure.
[0016] The concrete spalling damage structure is laid out using polystyrene foam boards. To ensure that the damage fits the actual situation, a utility knife is used to carve uneven areas on the back of the polystyrene foam board. At the same time, a groove is reserved on the side of the polystyrene foam board close to the stirrups to make the polystyrene foam board fit the steel cage more closely. Spray foam is used to fill the gap between the polystyrene foam board and the steel cage to ensure sealing and prevent leakage when pouring concrete.
[0017] The crack damage structure utilizes a four-point loading test after the beam is cast and cured. The crack damage is controlled based on the load-bearing capacity. The beam is placed on a test frame, ensuring the support points at both ends are positioned as designed. Clamps are used to secure the beam's ends to prevent lateral movement or rotation during the test. The loading device is placed at the pre-set loading points, ensuring the loading force is perpendicular to the beam's axis. Displacement gauges and strain gauges are installed, and a graded loading method is used. After each load is applied, the load is paused, and the displacement gauge and strain gauge data are recorded to observe whether the desired crack damage appears on the beam surface.
[0018] A method for preparing a RC beam damage model based on multi-gradient bending-shear bearing capacity control comprises the following steps:
[0019] S1, design the RC beam model, including its size, reinforcement ratio and other parameters to ensure the similarity between the model and the actual structure;
[0020] S2, making a RC beam casting mold according to the structural dimensions of the RC beam;
[0021] S3, tie the steel cage according to the reinforcement ratio, and attach strain gauges at key parts of the beam to measure the strain of the beam;
[0022] S4. Tie the foam board to the steel cage. According to the location, size, depth, and shape of the concrete spalling damage, make a cubic foam board that meets the requirements. Then mark it on the steel cage and use wire to fix the cubic foam board to the marked position of the steel cage.
[0023] S5, preparing concrete by mixing cement, water, and sand in a certain ratio;
[0024] S6, pouring of the RC beam damage model, filling the concrete prepared in S5 into the mold of S2 for pouring. The pouring process is to pour roughly first, then pour additionally while vibrating, and then smooth the pouring surface after pouring.
[0025] S7, curing the RC beam damage model. Seven days after the pouring is completed, the mold is removed and the RC beam damage model is watered and cured every day.
[0026] After curing, a four-point, graded loading test is conducted to control the crack damage according to the load capacity. The beam is placed on the test frame and fixed at both ends with a clamp. The loading device is then positioned at the preset loading points. Displacement gauges and strain gauges are installed. The beam is loaded in stages, and the load is paused after each load. The displacement gauge and strain gauge data are recorded to observe whether the desired crack damage appears on the beam surface.
[0027] In view of this, compared with the prior art, the beneficial effects of the present invention are:
[0028] (1) In this application, due to the low cost, low processing difficulty and easy molding of foam materials, models with preset damage shapes and sizes can be quickly produced according to needs, which is convenient for controlling and comparing structural behaviors under different damage conditions and making damaged beams that are exactly the same as the actual situation.
[0029] (2) In this application, high-precision simulation using a multi-gradient damage model can more accurately simulate the mechanical behavior of RC beams at different damage stages and improve the accuracy of damage assessment.
[0030] (3) In this application, the bearing capacity control can more intuitively reflect the degradation process of the bearing capacity by controlling the bending and shear bearing capacity of the model under different damage gradients, providing a basis for structural design and evaluation.
[0031] (IV) In this application, the method has strong adaptability and is applicable to RC beams of different types and sizes, and has good versatility and applicability. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 FIG1 is a schematic diagram of a RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0033] Figure 2 Shown is a second schematic diagram of an RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0034] Figure 3 Shown is a third schematic diagram of the RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0035] Figure 4 Shown is a fourth schematic diagram of an RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0036] Figure 5 Shown is a fifth schematic diagram of the RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0037] Figure 6 Shown is a sixth schematic diagram of an RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0038] Figure 7 FIG7 is a schematic diagram of the RC beam damage model based on the multi-gradient bending-shear bearing capacity control provided by the present invention;
[0039] Figure 8 FIG8 is a schematic diagram of an RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0040] Figure 9 FIG9 is a ninth schematic diagram of an RC beam damage model based on multi-gradient bending-shear bearing capacity control provided by the present invention;
[0041] Figure 10 Shown are the internal structure diagrams of RC beam damage models 1 and 5;
[0042] Figure 11 The figure shows the internal structure of RC beam damage model 2;
[0043] Figure 12 Shown are the internal structure diagrams of RC beam damage models three and six;
[0044] Figure 13 Shown are the internal structure diagrams of RC beam damage models four and seven;
[0045] Figure 14 Shown is the internal structure diagram of RC beam damage model eight;
[0046] Figure 15 Shown is the internal structure diagram of RC beam damage model nine.
[0047] icon:
[0048] 1-RC beam damage model one; 2-RC beam damage model two; 3-RC beam damage model three; 4-RC beam damage model four; 5-RC beam damage model five; 6-RC beam damage model six; 7-RC beam damage model seven; 8-RC beam damage model eight; 9-RC beam damage model nine; 10-first steel cage; 11-first foam board; 12-second foam board; 13-second steel cage; 14-third foam board; 15-fourth foam board. DETAILED DESCRIPTION
[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0050] See also Figure 1-15 , the utility model provides the following embodiments:
[0051] A RC beam damage model based on multi-gradient bending-shear bearing capacity control includes an RC beam damage model with concrete spalling, an RC beam damage model with cracks and mixed soil spalling, and an RC beam damage model with cracks. Each model is composed of a first steel cage 10, a second steel cage 13, mixed soil, a crack damage structure, and a concrete spalling damage structure. The concrete spalling damage structure is arranged using polystyrene foam boards, and the polystyrene foam boards are divided into a first foam board 11, a second foam board 12, a third foam board 14, and a fourth foam board 15. Each model is divided into RC beam damage model 1, RC beam damage model 2, RC beam damage model 3, RC beam damage model 4, RC beam damage model 5, RC beam damage model 6, RC beam damage model 7, RC beam damage model 8, and RC beam damage model 9. The concrete spalling damage structure of RC beam damage model 1 is rectangular and is located in the bending section of the RC beam, thereby controlling the bending bearing capacity of the RC beam. Degradation, the shape of the concrete spalling damage structure of the RC beam damage model 2 is a parallelogram and is located in the bending section of the RC beam, the shape of the concrete spalling damage structure of the RC beam damage model 5 is a rectangle and is located in the bending section of the RC beam, and the RC beam damage model 5 is provided with a crack damage structure, the RC beam damage model 8 is provided with a crack damage structure, the shape of the concrete spalling damage structure of the RC beam damage model 3 is a rectangle and is located in the shear section of the RC beam, so as to control the degradation of the shear bearing capacity of the RC beam, the shape of the concrete spalling damage structure of the RC beam damage model 4 is a parallelogram, the shape of the concrete spalling damage structure of the RC beam damage model 6 is a rectangle and is located in the shear section of the RC beam, and the RC beam damage model 6 is provided with a crack damage structure, the shape of the concrete spalling damage structure of the RC beam damage model 7 is a parallelogram, and the RC beam damage model 7 is provided with a crack damage structure, and the RC beam damage model 9 is provided with a crack damage structure.
[0052] Among them, the RC beam damage model 1 is composed of a first steel cage 10 and a first foam plate 11. The first foam plate 11 is located in the upper part of the RC beam span, 80 mm away from the upper surface of the beam; the RC beam damage model 2 is based on the RC beam damage model 1, and the first foam plate 11 is replaced by the second foam plate 12, taking into account the damage of different shapes; the RC beam damage model 3 is composed of a second steel cage 13 and two third foam plates 14. The third foam plates 14 are located in the left and right shear spans of the RC beam, 80 mm away from the upper surface of the beam; the RC beam damage model 4 is composed of a second steel cage 13 and two fourth foam plates 15. The third foam plate 14 is located in the left and right shear spans of the RC beam, and the fourth foam plate 15 is close to the two ends and the bottom of the beam; the RC beam damage model 5 is based on the RC beam damage model 1 On the basis of the above, after the beam is cured, a four-point, graded loading test is used to add crack damage. At the same time, pay attention to observe the cracks when loading the beam, and immediately suspend loading when the designed cracks appear; RC beam damage model 6 6 is based on the RC beam damage model 3 3 and adds a crack damage structure. The crack damage structure adopts the same loading method as the RC beam damage model 5 5; RC beam damage model 7 7 is based on the RC beam damage model 4 4 and adds crack damage. The crack damage structure adopts the same loading method as the RC beam damage model 5 5. RC beam damage model 8 8 is composed of a first steel cage 10, and then adds crack damage. The adding method is the same as the RC beam damage model 5 5; RC beam damage model 9 9 is composed of a second steel cage 13, and then adds crack damage. The adding method is the same as the RC beam damage model 5 5.
[0053] Use a utility knife to carve grooves and uneven shapes on the back of the first, second, third, and fourth foam boards (11, 12, 14, and 15) to align with the rebar cage. Tie wire is then used to tightly secure the foam boards to the rebar cage, ensuring they do not shift during concrete pouring. Additional tie wire is used to reinforce key areas and improve overall stability. Spray foam is then used to fill any gaps or cracks between the foam boards and the rebar cage, ensuring a tight seal and preventing leakage during concrete pouring.
[0054] After the beam is cast and cured, a four-point loading test is performed to control the crack damage according to the load-bearing capacity. The beam is placed on the test frame, ensuring that the support points at both ends are positioned as designed. Fixtures are used to secure the beam at both ends to prevent lateral movement or rotation during the test. The loading device is placed at the preset loading points, ensuring that the loading force is perpendicular to the beam axis. Displacement gauges and strain gauges are installed, and a graded loading method is used. Pause after each application of a certain load, record the displacement gauge and strain gauge data, and observe whether the desired crack damage appears on the beam surface.
[0055] A method for preparing a RC beam damage model based on multi-gradient bending-shear bearing capacity control is carried out in the following steps:
[0056] S1, determine the size of the RC beam model, including its size, reinforcement ratio and other parameters to ensure the similarity between the model and the actual structure.
[0057] S2, making the RC beam casting mold according to the structural dimensions of the RC beam.
[0058] S3: Tie the rebar cage according to the reinforcement ratio and apply strain gauges to key beam locations. First, verify that the rebar type, diameter, and length meet the design requirements. Prepare the binding wire and ensure it is of good quality and resistant to breakage. Then, arrange the main bars according to the design drawings at the predetermined spacing and length to form the rebar cage. The main bars should be placed on spacers, ensuring the required distance (cover thickness) from the mold. Stirrups should be placed over the main bars at the specified spacing to ensure accurate placement. The stirrups should be perpendicular to the main bars to ensure structural stability. Once the positions are determined, use wire to tie the intersections of the main bars and stirrups. Figure-eight or cross knots are typically used for secure tying. Tie the bars starting from one end and working toward the other, ensuring all intersections are secure. After tying, check that the overall size and shape of the rebar cage meet the design requirements. Check that the tying points are secure. If any loose or untied areas are found, adjust and reinforce them promptly.
[0059] Prepare sandpaper, alcohol, cotton swabs, a strain gauge, epoxy resin, and gauze. Use sandpaper to polish the rebar surface to remove oil, rust, and oxide layers. Gently wipe the rebar surface with a cotton swab dipped in alcohol and allow it to completely dry. Apply a thin layer of primer to the bottom of the strain gauge. Once it is partially dry, attach it to the polished rebar surface, ensuring a tight fit. Use gauze to soak up the epoxy resin and wrap the strain gauge to prevent damage during the concrete pouring process. Test the strain gauge with an ohmmeter to ensure it is functioning properly.
[0060] In step S4, tie the concrete spalling damage to the rebar cage. By controlling the location, size, depth, and shape of the damage, the degradation of the RC beam's flexural and shear bearing capacity can be controlled. Use polystyrene foam sheets to create specific damage. First, select polystyrene foam sheets of the appropriate shape and thickness based on your needs. Prepare scotch tape, tie wire (to secure the foam), and spray foam (to fill gaps and cracks). Then, cut the desired foam shape and mark the location of the shape on the foam sheet. Use a utility knife to cut the foam sheet according to the markings to ensure accurate dimensions. To more closely resemble actual conditions, use a utility knife to create uneven shapes on the side of the foam sheet near the rebar cage.
[0061] Then, mark the placement of the foam sheet on the rebar cage and place the cut foam sheet on the cage, ensuring it fits perfectly. Wrap the foam sheet with clear tape to facilitate securing it with tying wire. If the foam sheet is thicker than the protective layer, use a knife to cut appropriate grooves to ensure a better fit. Use tying wire to tightly tie the foam sheet to the rebar cage to ensure it does not shift during the concrete pour. Use additional tying wire to reinforce key areas and improve overall stability. Then, use spray foam to fill any gaps or cracks between the foam sheet and the rebar cage to ensure a seal and prevent leakage during the concrete pour.
[0062] Check the entire structure to ensure all parts are securely fastened and there are no obvious gaps or looseness. Make adjustments or reinforcements if necessary.
[0063] S5, Prepare Concrete: Mix cement, water, and sand in a specific ratio. According to the design requirements and mix ratio, mix cement, sand, gravel, and water in the appropriate proportions. Mix the concrete evenly to ensure all ingredients are thoroughly mixed. Add appropriate amounts of admixtures, such as water reducers and retarders, to improve concrete properties.
[0064] S6: Pour the concrete. Ensure the mold is securely in place and level. The mold should be flat, clean, and have tight joints to prevent leakage. Place the rebar cage with foam board inside the mold. Check that the rebar is properly tied and positioned accurately. Then, use a concrete pump, crane, or chute to deliver the concrete to the mold to ensure quality during transportation.
[0065] During the pouring process, the concrete should be prevented from falling too far to prevent segregation. A vibrating rod should be used to vibrate the concrete to remove air bubbles and increase its density. The vibrator should be inserted into the concrete, but avoid contact with the mold or rebar. The vibration time should not be too long to prevent the concrete from delaminating. After the concrete is poured, use a wooden trowel to smooth the surface to ensure a smooth surface.
[0066] S7: Curing the concrete. This is usually done by covering it with a film, sprinkling water, or using a curing agent to keep the concrete surface moist and prevent rapid evaporation of surface moisture. Once the concrete reaches a certain strength, the mold is removed.
[0067] S8, after curing is completed, a four-point, graded loading test is used to add crack damage. Place the beam on the test frame to ensure that the position of the support points at both ends is consistent with the design. Use clamps to fix the ends of the beam to prevent lateral movement or rotation of the beam during the test. Place the loading device on the preset loading point to ensure that the loading force is perpendicular to the axis of the beam. Install the displacement meter and strain gauge, and use a graded loading method. Pause after each load, record the data of the displacement meter and strain gauge, and observe whether the required crack damage appears on the beam surface.
[0068] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
[0069] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.
Claims
1. A RC beam damage model based on multi-gradient bending-shear capacity control, characterized by: The invention comprises a RC beam damage model with concrete spalling, a RC beam damage model with cracks and mixed soil spalling, and a RC beam damage model with cracks, and each model is composed of a first steel cage (10), a second steel cage (13), mixed soil, a crack damage structure, and a concrete spalling damage structure. The concrete spalling damage structure is arranged using polystyrene foam boards, and the polystyrene foam boards are divided into a first foam board (11), a second foam board (12), a third foam board (14), and a fourth foam board (15). Each model is divided into RC beam damage model one (1), RC beam damage model two (2), RC beam damage model three (3), RC beam damage model four (4), RC beam damage model five (5), RC beam damage model six (6), RC beam damage model seven (7), RC beam damage model eight (8), and RC beam damage model nine (9).
2. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The concrete spalling damage structure of the RC beam damage model 1 (1) is rectangular in shape and is located in the bending section of the RC beam, thereby controlling the degradation of the flexural bearing capacity of the RC beam.
3. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The concrete spalling damage structure of the RC beam damage model 2 (2) is in the shape of a parallelogram and is located in the curved section of the RC beam.
4. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The concrete spalling damage structure of the RC beam damage model five (5) is in the shape of a rectangle and is located in the curved section of the RC beam, and a crack damage structure is provided on the RC beam damage model five (5).
5. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The RC beam damage model eight (8) is provided with a crack damage structure.
6. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The concrete spalling damage structure of the RC beam damage model three (3) is rectangular in shape and is located in the shear section of the RC beam, thereby controlling the degradation of the shear bearing capacity of the RC beam.
7. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The shape of the concrete spalling damage structure of the RC beam damage model four (4) is a parallelogram.
8. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The concrete spalling damage structure of the RC beam damage model six (6) is in the shape of a rectangle and is located in the shear section of the RC beam, and a crack damage structure is provided on the RC beam damage model six (6).
9. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1 is characterized in that: The concrete spalling damage structure of the RC beam damage model seven (7) is in the shape of a parallelogram, and a crack damage structure is provided on the RC beam damage model seven (7).
10. The RC beam damage model based on multi-gradient bending-shear capacity control according to claim 1, characterized in that: The RC beam damage model nine (9) is provided with a crack damage structure.