A method for detecting bonding strength of filling materials

Abstract

The present invention relates to the field of detection, and in particular to a method for detecting the bonding strength of filling materials. The content includes: measuring the initial bonding strength of the filling material through a standard tensile test; preparing samples required for dynamic loading and applying dynamic loading; introducing a dynamic loading bonding strength correction algorithm, based on the vibration frequency of dynamic loading and the amplitude of dynamic loading, combined with the initial bonding strength, to obtain the cumulative normalized energy density; based on the cumulative normalized energy density, calculating the dynamic loading correction factor; based on the dynamic loading correction factor, correcting the initial bonding strength to obtain the corrected bonding strength. It solves the technical problems that traditional detection methods are mostly static tests, which cannot fully simulate actual working conditions and are difficult to reflect the true performance under dynamic working conditions; the quantification of dynamic loading damage effects is insufficient; and the consistency and reliability of test results are insufficient.

Description

Technical Field

[0001] The present invention relates to the field of detection, and in particular to a method for detecting the bonding strength of a filling material. Background Art

[0002] As an important material widely used in engineering, construction, aerospace, automobile manufacturing, medical devices and other fields, the bond strength of filler materials is one of the key indicators for evaluating their performance and reliability. Bond strength not only affects the actual use effect of filler materials, but is also directly related to their durability, safety and functionality in specific application scenarios. Therefore, the development of scientific and accurate bond strength testing methods is of great significance to ensuring the quality of filler materials and promoting the advancement of related technologies. At present, the testing methods for the bond strength of filler materials mainly include tensile tests, shear tests, peel tests and other non-standardized test methods. Although these methods have met the needs of bond strength testing to a certain extent, they still have some limitations. For example, traditional test methods are usually targeted at specific stress modes and cannot fully reflect the performance of filler materials under complex stress states. The test results are greatly affected by specimen preparation and environmental conditions. For new composite filler materials or nano-modified materials, existing methods may not be able to accurately capture their microscopic interface characteristics. In recent years, with the advancement of non-destructive testing technology, sensor technology and artificial intelligence, the testing methods for the bond strength of filler materials are developing towards high precision, intelligence and non-destructiveness.

[0003] Testing the bond strength of filling materials is a key research topic in materials science and engineering. The underlying technologies encompass material properties, mechanical testing, equipment development, and standardization. With the increasing variety of filling materials and the increasing complexity of their applications, traditional tensile, shear, and peel testing methods are no longer fully sufficient, necessitating the development of more precise and comprehensive testing technologies.

[0004] In summary, traditional methods for testing the bond strength of filling materials still have the following problems: traditional testing methods are mostly static tests, which cannot fully simulate actual working conditions and have difficulty reflecting the true performance under dynamic working conditions; the quantification of dynamic loading damage effects is insufficient; and the consistency and reliability of test results are insufficient. Summary of the Invention

[0005] The present invention provides a method for testing the bonding strength of filling materials to solve the technical problems that traditional testing methods are mostly static tests, cannot fully simulate actual working conditions, have difficulty reflecting the true performance under dynamic working conditions; are insufficient in quantifying the damage effects of dynamic loading; and have insufficient consistency and reliability in test results.

[0006] A method for testing the bonding strength of a filling material according to the present invention specifically includes the following technical solutions:

[0007] A method for detecting the bonding strength of a filling material comprises the following steps:

[0008] S1. Measure the initial bond strength of the filling material by a standard tensile test;

[0009] S2. Prepare the samples required for dynamic loading and apply dynamic loading; introduce a dynamic loading bond strength correction algorithm, and obtain the cumulative normalized energy density based on the dynamic loading vibration frequency and dynamic loading amplitude combined with the initial bond strength; calculate the dynamic loading correction factor based on the cumulative normalized energy density; and correct the initial bond strength based on the dynamic loading correction factor to obtain the corrected bond strength.

[0010] Preferably, the S1 specifically includes:

[0011] The standard tensile test obtains a cured sample through standardized substrate preparation, coating and curing processes; applies a tensile load to the cured sample to obtain an average maximum tensile force; and obtains the initial bond strength based on the average maximum tensile force and the bond area.

[0012] Preferably, the S2 specifically includes:

[0013] According to the standard tensile test, the same batch of filling materials is selected, and standardized substrate preparation, coating and curing processes are carried out to obtain samples required for dynamic loading. Dynamic loading is applied to the samples in sequence, and tensile tests are performed on all samples that have completed dynamic loading to obtain the average maximum tensile force after dynamic loading.

[0014] Preferably, the S2 specifically includes:

[0015] In the implementation of the dynamic loading bond strength correction algorithm, for each set of dynamic loading, the maximum vibration velocity is calculated based on the dynamic loading vibration frequency and dynamic loading amplitude. Based on the maximum vibration velocity, combined with the filling material density and initial bond strength, the normalized energy density of each dynamic loading set is obtained. The normalized energy densities of all dynamic loading sets are summed to obtain the cumulative normalized energy density.

[0016] Preferably, the S2 specifically includes:

[0017] Based on the cumulative normalized energy density, the energy absorption coefficient of the filling material is introduced and combined with the exponential decay function to obtain the dynamic loading correction factor; based on the dynamic loading correction factor, the theoretically predicted strength loss ratio is calculated.

[0018] Preferably, the S2 specifically includes:

[0019] The relative strength loss rate was calculated based on the initial bond strength and bond area measured under the standard tensile test and the average maximum tensile force after dynamic loading measured under dynamic loading conditions.

[0020] Preferably, the S2 specifically includes:

[0021] The absolute deviation between the relative strength loss rate and the theoretically predicted strength loss ratio is calculated, and the absolute deviation is compared with the preset absolute deviation threshold. When the absolute deviation is less than or equal to the absolute deviation threshold, it means that the dynamic loading correction factor is valid and the dynamic loading bond strength correction algorithm is reliable. Otherwise, it means that the dynamic loading correction factor is invalid and the dynamic loading bond strength correction algorithm is unreliable.

[0022] Preferably, the S2 specifically includes:

[0023] Multiply the initial bond strength by the dynamic loading correction factor to obtain the corrected bond strength as the final test result.

[0024] The beneficial effects of the technical solution of the present invention are:

[0025] 1. Through standard tensile testing, using standardized substrates, strict surface treatment and uniform coating processes, combined with constant temperature and humidity curing and high-precision vibration testing machines for testing, it ensures that the initial bond strength measurement results of the filling material under static conditions are accurate and reliable, eliminating the interference of interface defects, uneven thickness and environmental fluctuations, and obtaining data reflecting the true bonding performance of the material, providing a reliable benchmark for subsequent dynamic performance evaluation. It is suitable for static performance testing of various filling materials (such as epoxy resin and silicone adhesive).

[0026] 2. Through the dynamic loading bond strength correction algorithm, based on normalized energy density and exponential decay function, the cumulative damage effect of complex dynamic loading (such as wind load and mechanical vibration) on the bond strength of the filling material is quantified. By simulating the complex vibration environment in actual working conditions, the dynamic loading correction factor is calculated, and the strength retention ratio of the filling material under dynamic conditions is obtained. This breaks through the limitation of traditional static testing that cannot reflect dynamic damage, and significantly improves the guiding significance of the test results for actual application scenarios (such as building seals, medical implants, and industrial seals).

[0027] 3. By comparing the relative strength loss rate measured experimentally with the theoretically predicted strength loss ratio, the accuracy of the dynamic loading correction factor was verified, ensuring that the dynamic loading bond strength correction algorithm can truly reflect the impact of dynamic loading on bond strength. A reliable dynamic loading correction factor was obtained, which provides a scientific basis for the dynamic performance evaluation of filling materials and enhances the practicality and credibility of the detection method.

[0028] 4. By combining the initial bond strength with the dynamic loading correction factor, the corrected bond strength is calculated, reflecting the true performance of the filling material under actual dynamic working conditions. It comprehensively considers static performance and dynamic damage effects, solves the deficiency of traditional tests that cannot simulate complex working conditions such as vibration and fatigue, obtains bond strength data that is closer to actual application, and fills the technical gap that traditional testing methods cannot evaluate dynamic damage effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of a method for detecting the bonding strength of a filling material according to the present invention. DETAILED DESCRIPTION

[0030] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments 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 shall fall within the scope of protection of the present invention.

[0031] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0032] The specific scheme of the method for detecting the bonding strength of a filling material provided by the present invention is described in detail below with reference to the accompanying drawings.

[0033] Refer to the attached Figure 1 , which shows a flow chart of a method for detecting the bonding strength of a filling material provided by one embodiment of the present invention, the method comprising the following steps:

[0034] S1. Measure the initial bond strength of the filling material by a standard tensile test;

[0035] In order to measure the initial bond strength of the filling material, a standard tensile test is performed to ensure that the test results can reflect the actual performance of the filling material under static conditions;

[0036] The standard tensile test uses two standard substrates (such as stainless steel or ceramic plates) with dimensions of 100 mm × 50 mm × 5 mm to ensure geometric consistency and reduce uneven stress distribution. The substrate surfaces are wiped with acetone to remove oil and impurities to ensure a clean bonding interface. The surface roughness of the substrates is measured using a surface roughness meter, with a roughness parameter Ra required to be less than 0.5 microns to ensure consistency of the bonding interface and stability of the bonding effect. Standardized preparation of the substrates can ensure uniformity of the bonding interface, roughness control can reduce local stress concentration, and acetone cleaning can remove surface contaminants to enhance the adhesion of the bonding material. Standardized preparation, roughness control, and acetone cleaning ensure that the initial bond strength measurement results reflect the true performance of the filling material and reduce the impact of interface defects on the bonding strength of the filling material.

[0037] A filling material (such as an epoxy resin-based sealant) is evenly applied between two standard substrates to obtain a coated sample. The filling material coating process requires the use of a dedicated fixture (such as a thickness control gasket) and the bond layer thickness is controlled to be 0.5 mm ± 0.05 mm. The coating process must ensure that the filling material is evenly distributed to avoid bubbles or localized uneven thickness. This prevents uneven stress distribution caused by thickness variations, which may affect the filling material bond strength measurement.

[0038] Place the coated sample in a constant temperature and humidity chamber, set the temperature to 23℃±2℃, and the relative humidity to 50%±5%, and cure for 24 hours. During the curing process, the environmental conditions must be monitored to ensure that the temperature and humidity are stable to avoid incomplete curing of the material or changes in performance due to environmental fluctuations. After the curing is completed, the coated sample achieves stable bonding performance, the molecular structure inside the bonding layer tends to be stable, and it has the ability to withstand tensile loads, thus obtaining a cured sample.

[0039] Fix the cured sample in a universal testing machine (such as Instron 5567, force sensor accuracy ±0.5%). Use a fixture to ensure that the cured sample is vertically aligned to avoid stress offset caused by eccentric loading. Apply a tensile load at a constant tensile rate (5 mm / min) and record the maximum tensile force when the cured sample breaks. Repeat the test three times and take the average of the three maximum tensile forces (i.e., the average maximum tensile force) to reduce random errors and improve data reliability. Divide the average maximum tensile force by the bond area to obtain the initial bond strength, which is expressed as follows:

[0040]

[0041] in, Indicates the initial bond strength, which is used to reflect the bond strength of the filling material under static conditions (without dynamic loading); Indicates the average maximum tensile force, reflecting the load-bearing capacity of the filling material under static conditions; Indicates the bonding area between the filling material and the substrate, and is used to normalize the average maximum tensile force to calculate the bonding strength per unit area;

[0042] The initial bond strength of the filling material is accurately measured through a standard tensile test to ensure that the test results can reflect the true performance of the filling material under static conditions.

[0043] S2. Prepare the sample required for dynamic loading and apply dynamic loading; introduce a dynamic loading bond strength correction algorithm to obtain a cumulative normalized energy density based on the dynamic loading vibration frequency and dynamic loading amplitude, combined with the initial bond strength; calculate a dynamic loading correction factor based on the cumulative normalized energy density; and correct the initial bond strength based on the dynamic loading correction factor to obtain a corrected bond strength;

[0044] Since filling materials are subjected to complex dynamic loading (such as wind loads, mechanical vibrations, or cyclic stresses caused by human movement) in practical applications (such as building sealants, medical implant adhesive layers, or industrial seals), fatigue damage may occur at the bonding interface, reducing the bond strength. The initial bond strength measured by a standard tensile test only reflects the performance of the filling material under ideal static conditions and cannot represent the dynamic damage effects under actual working conditions. Therefore, a dynamic loading bond strength correction algorithm is needed to accurately quantify the cumulative damage effect of continuous dynamic loading on the bond strength of the filling material and calculate a dynamic loading correction factor. Based on the dynamic loading correction factor, the initial bond strength is corrected to obtain the corrected bond strength.

[0045] The dynamic loading requires selecting the same batch of filling materials according to the standard tensile test, and performing standardized substrate preparation, coating and curing processes to ensure material and process consistency and obtain samples required for dynamic loading; using a high-precision vibration testing machine, multiple groups of dynamic loads are applied to the sample in sequence to simulate the complex vibration environment in actual working conditions, such as the influence of wind load or mechanical vibration on the building structure; dynamic loading is applied in sequence from low to high vibration frequency, and after each group of loading is completed, it is paused to check whether there are obvious cracks or falling off on the surface of the sample. If the sample is seriously damaged, the sample needs to be re-prepared to ensure the effectiveness of the test. The sequential design ensures the gradualness of cumulative damage, which is consistent with the complex vibration characteristics of actual working conditions; the sample that has completed all dynamic loading is re-fixed in the universal testing machine and tested at the same tensile rate as in S1. The single maximum tensile force after dynamic loading is measured, and the average value is taken after repeating the test three times to obtain the average maximum tensile force after dynamic loading, so as to improve accuracy and reduce random errors;

[0046] The dynamic loading bond strength correction algorithm is based on the energy accumulation damage theory in the field of material mechanics and fatigue damage, and quantifies the cumulative damage effect of dynamic loading; for each group of dynamic loading, the maximum vibration velocity is calculated based on the vibration frequency and amplitude of the dynamic loading; the kinetic energy density of a single vibration is calculated by combining the density of the filling material and the square of the maximum vibration velocity; the density of the filling material is measured experimentally and can be obtained by a densitometer, which reflects the quality characteristics of the filling material; the kinetic energy density of a single vibration is multiplied by the number of vibration cycles of dynamic loading to obtain the energy density of each group of dynamic loading, and the number of vibration cycles of dynamic loading is set according to the working condition requirements; the energy density of each group of dynamic loading is divided by the initial bond strength to obtain the normalized energy density; the normalized energy densities of all dynamic loading groups are summed to obtain the cumulative normalized energy density, which reflects the overall energy input of the sample to the continuous dynamic loading; the cumulative normalized energy density is multiplied by the energy absorption coefficient of the filling material, and exponential decay is introduced to obtain a The value within this range is called the dynamic loading correction factor, which represents the retained proportion of bond strength after dynamic loading. The energy absorption coefficient of the filling material depends on the material type, such as epoxy resin, silicone adhesive, etc., and is determined through vibration energy absorption experiments. When the dynamic loading correction factor is close to 1, it means that the cumulative normalized energy density is very small, the damage is slight, and the bond strength is almost not weakened. When the dynamic loading correction factor is close to 0, it means that the cumulative normalized energy density is very large, the damage is severe, and the bond strength is significantly reduced.

[0047] The calculation formula of the dynamic loading correction factor is:

[0048]

[0049] in, It represents the dynamic loading correction factor, which is used to reflect the retention ratio of bond strength after dynamic loading; Represents the natural exponential base, used to construct the exponential decay function; Indicates the energy absorption coefficient of the filling material, which is used to reflect the damage sensitivity of the filling material to the cumulative normalized energy density. The value range is to ; Indicates dynamic loading of all groups (from arrive ) accumulation; Indicates the total number of groups loaded dynamically; Indicates the The normalized energy density of group dynamic loading is used to reflect the damage potential of vibration energy input relative to the initial bond strength, which is derived from the classic kinetic energy formula; It represents the constant coefficient of the kinetic energy formula, which is used to calculate the kinetic energy density of a single vibration; Indicates the density of the filling material, measured by a densitometer; Indicates the Maximum vibration velocity of the group under dynamic loading; Indicates the The vibration frequency of the group under dynamic loading is used to reflect the vibration speed; Indicates the Amplitude of group dynamic loading; Indicates the Number of vibration cycles for group dynamic loading;

[0050] Furthermore, the relative strength loss rate was calculated based on the initial bond strength and bond area measured under the standard tensile test and the average maximum tensile force after dynamic loading measured under dynamic loading conditions;

[0051] Specifically, the average maximum tensile force after dynamic loading was subtracted from the initial bond strength and divided by the bond area, and then further divided by the initial bond strength to obtain the relative strength loss rate, which reflects the relative weakening ratio of the bond strength after dynamic loading.

[0052] The calculation formula for relative strength loss rate is:

[0053]

[0054] in, Indicates the relative strength loss rate; represents the average maximum tensile force after dynamic loading; Indicates the bond strength of the filling material after dynamic loading;

[0055] Furthermore, the effectiveness of the dynamic loading correction factor was confirmed by comparing the relative strength loss rate with the theoretically predicted strength loss ratio to ensure that the dynamic loading bond strength correction algorithm can accurately reflect the impact of dynamic loading on bond strength. The theoretically predicted strength loss ratio is obtained by subtracting the dynamic loading correction factor from 1 to reflect the theoretical strength loss ratio caused by dynamic loading.

[0056] Specifically, the absolute deviation between the relative strength loss rate and the theoretically predicted strength loss ratio is calculated, and the absolute deviation is compared with the preset absolute deviation threshold. If the absolute deviation is less than or equal to the absolute deviation threshold, it means that the dynamic loading correction factor is valid and the dynamic loading bond strength correction algorithm is reliable. Otherwise, it means that the dynamic loading correction factor is invalid and the dynamic loading bond strength correction algorithm is unreliable. The formula is expressed as follows:

[0057]

[0058] in, Indicates the relative strength loss rate; represents the theoretically predicted strength loss ratio; Indicates the absolute deviation threshold, such as 0.01, which is set according to expert experience;

[0059] The dynamic loading bond strength correction algorithm uses cumulative normalized energy density and exponential decay function to quantify the impact of complex dynamic loading;

[0060] In order to evaluate the actual performance of the filling material under dynamic loading conditions, the initial bond strength is multiplied by the dynamic loading correction factor to obtain the corrected bond strength. This is used as the final test result to evaluate the performance of the filling material under actual dynamic conditions (such as building vibration and mechanical fatigue). The calculation formula is as follows:

[0061]

[0062] in, It represents the corrected bond strength, which is the actual bond strength after dynamic loading and is used to reflect the performance of the filling material under a complex vibration environment;

[0063] Combining static performance with dynamic damage effects to output bond strength that reflects real working conditions can address the limitation of traditional static testing that cannot simulate the impact of dynamic loading (such as vibration) on material properties.

[0064] In summary, a method for testing the bonding strength of filling materials is completed.

[0065] The order in which the embodiments of the invention are presented is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0066] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for testing the bonding strength of a filling material, characterized in that: The following steps are involved: S1. Measure the initial bond strength of the filling material by a standard tensile test; S2. Selecting the same batch of filling materials according to the standard tensile test and performing standardized substrate preparation, coating, and curing processes to obtain samples required for dynamic loading, and applying dynamic loading to the samples in sequence. Tensile testing is performed on all samples that have completed dynamic loading to obtain the average maximum tensile force after dynamic loading; A dynamic loading bond strength correction algorithm is introduced. For each set of dynamic loading, the maximum vibration velocity is calculated based on the dynamic loading vibration frequency and dynamic loading amplitude. Based on the maximum vibration velocity, combined with the filling material density and initial bond strength, the normalized energy density of each dynamic loading group is obtained; the normalized energy density of all dynamic loading groups is summed to obtain the cumulative normalized energy density; based on the cumulative normalized energy density, the energy absorption coefficient of the filling material is introduced and combined with the exponential decay function to calculate the dynamic loading correction factor, which is calculated as follows: ； in, represents the dynamic loading correction factor; Indicates the energy absorption coefficient of the filling material; Indicates the total number of groups loaded dynamically; Indicates the density of the filling material; Indicates the The vibration frequency of the group under dynamic loading; Indicates the Amplitude of group dynamic loading; Indicates the Number of vibration cycles for group dynamic loading; Indicates initial bond strength; Based on the dynamic loading correction factor, the theoretically predicted strength loss ratio is calculated; based on the initial bond strength and bonding area measured under the standard tensile test and the average maximum tensile force after dynamic loading measured under dynamic loading conditions, the relative strength loss rate is calculated; the absolute deviation between the relative strength loss rate and the theoretically predicted strength loss ratio is calculated, and the absolute deviation is compared with the preset absolute deviation threshold. When the absolute deviation is less than or equal to the absolute deviation threshold, it indicates that the dynamic loading correction factor is valid and the dynamic loading bond strength correction algorithm is reliable. Otherwise, it indicates that the dynamic loading correction factor is invalid and the dynamic loading bond strength correction algorithm is unreliable; based on the dynamic loading correction factor, the initial bond strength is corrected to obtain the corrected bond strength.

2. A method for detecting bonding strength of a filling material according to claim 1, characterized in that: Said S1 specifically includes: The standard tensile test obtains a cured sample through standardized substrate preparation, coating and curing processes; applies a tensile load to the cured sample to obtain an average maximum tensile force; and obtains the initial bond strength based on the average maximum tensile force and the bond area.

3. A method for detecting bonding strength of a filling material according to claim 1, characterized in that: Said S2 specifically includes: Multiply the initial bond strength by the dynamic loading correction factor to obtain the corrected bond strength as the final test result.

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