Special electronic tensile machine for non-woven fabric and tensile testing system

Abstract

The invention relates to the field of tension testing, in particular to a special electronic tensile machine for non-woven fabric and a tensile testing system. Comprising a data acquisition module used for determining a state tension data sequence and a state tension distance sequence; the data analysis module is used for calculating a tension slope sequence; determining the real stretching degree of the target moment; obtaining a monotonic tension data segment and a tension distance data segment; calculating the change difference between each monotonic tension data segment and the corresponding tension distance data segment; constructing a three-dimensional space coordinate system, and determining a three-dimensional coordinate point set; obtaining the transition smoothness of each vector in a three-dimensional space coordinate system; determining a target vector from the vectors, and calculating the rupture degree of the target moment; and the data adjusting module is used for adjusting the operation termination condition of the electronic tensile machine according to the fracture degree at the target moment. The non-woven fabric tension detection precision of the electronic tensile machine can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tension testing, in particular to a special electronic tension testing machine for non-woven fabric and a tension testing system. BACKGROUND

[0002] Cables are widely used in current transmission of various electrical equipment. During current transmission, cables are subject to external environmental erosion and wear for a long time. To solve this daily wear and tear problem, the existing technology wraps one or more layers of cloth materials around the cable to achieve the purpose of protection. The materials used for wrapping now mainly include woven tape, PVC tape, glass fiber tape and non-woven fabric. Among them, non-woven fabric is better applied in cable protection due to its excellent flexibility (stronger than glass fiber tape), air permeability (stronger than PVC tape), insulation and temperature resistance (stronger than woven tape).

[0003] Non-woven fabric is a kind of sheet material formed by connecting high molecular polymer and fibrous material (such as short fiber and filament) together through physical, chemical or mechanical methods, which has soft, porous and three-dimensional structure. Unlike traditional woven cloth, the fibers inside non-woven fabric are randomly formed, and the density, thickness and fiber distribution inside are not uniform. Therefore, after the production of non-woven fabric, an electronic tension testing machine is usually used to detect the tension, and the tension applied when the damage occurs is used to judge whether the non-woven fabric has quality problems.

[0004] When the existing technology uses an electronic tension testing machine to test the tension of non-woven fabric, the computer system connected with the tension testing machine will update the highest peak value of the detected tension in real time. When the tension decays to 50% of the highest peak value (default ratio), the system will default that the non-woven fabric has been broken at this time, and the tension testing machine will stop working. However, in actual scenarios, due to the uneven distribution of non-woven fabric material and internal fibers, the tension at which the non-woven fabric actually breaks may not be 50% of the highest peak value (may be greater than 50%, may be less than 50%), so that the accuracy of the electronic tension testing machine for non-woven fabric tension detection is not high. SUMMARY

[0005] The present application provides a special electronic tension testing machine for non-woven fabric and a tension testing system to solve the existing problems.

[0006] The special electronic tension testing machine for non-woven fabric and the tension testing system of the present application adopt the following technical solutions:

[0007] An embodiment of the present application provides a special electronic tension testing machine for non-woven fabric and a tension testing system, which comprises:

[0008] The data collection module is configured to determine a state tension data sequence and a state tension distance sequence according to tension data and a clamp distance of the electronic tension machine at each time point.

[0009] The data analysis module is configured to calculate a tension slope of each element in the state tension data sequence to obtain a tension slope sequence, determine a real stretching degree at a target time according to the tension slope sequence, obtain a monotonic tension data segment and a tension distance data segment according to the state tension data sequence and the state tension distance sequence, calculate a change gap of each monotonic tension data segment and a corresponding tension distance data segment according to the real stretching degree at the target time, the monotonic tension data segment and the tension distance data segment, construct a three-dimensional coordinate system, and determine a three-dimensional coordinate point set according to the monotonic tension data segment and the tension distance data segment, obtain transition smoothness of each vector in the three-dimensional coordinate system, wherein the vector is determined according to a position of an element in the three-dimensional coordinate point set in the three-dimensional coordinate system, and determine a target vector from the vector, and calculate a rupture degree at the target time according to the transition smoothness and the change gap of the target vector.

[0010] The data adjustment module is configured to adjust a running termination condition of the electronic tension machine according to the rupture degree at the target time.

[0011] Optionally, the data analysis module determines the real stretching degree at the target time according to the tension slope sequence, and specifically includes the following steps.

[0012] The data analysis module determines a slope change amount sequence and a slope change amount mean sequence according to the tension slope sequence.

[0013] The data analysis module obtains elements less than a preset slope change amount threshold in the slope change amount mean sequence to obtain an abnormal slope change amount sequence.

[0014] When the number of elements in the abnormal slope change amount sequence is equal to 0, it is determined that the non-woven fabric is in a normal stretching state, and the state tension data sequence and the state tension distance sequence are updated until the number of elements in the abnormal slope change amount sequence is not equal to 0.

[0015] When the number of elements in the abnormal slope change amount sequence is not equal to 0, the data analysis module obtains a tension overall deviation at a time point corresponding to a target element in the tension slope sequence, a number of historical stretching state time periods in the tension slope sequence, and a mean value of a tension overall deviation of each historical stretching state time period.

[0016] The data analysis module calculates the real stretching degree at the target time according to the tension overall deviation at the time point corresponding to the target element, the number of the historical stretching state time periods, and the mean value of the tension overall deviation of each historical stretching state time period.

[0017] Optionally, in the data analysis module, the slope change amount sequence and the slope change amount mean sequence are determined according to the tension slope sequence, and specifically include:

[0018] The difference between the (c+1)th element and the cth element in the tension slope sequence is determined as the slope change amount of the (c+1)th element.

[0019] The slope change amount of each element in the tension slope sequence is obtained, and the slope change amount sequence is obtained, wherein the (c+1)th element is not the first element in the tension slope sequence.

[0020] The (i)th to (i+n)th elements in the slope change amount sequence are obtained and averaged to obtain the local slope change amount mean of the ith element, wherein i and n are positive integers.

[0021] The local slope change amount mean of each element in the slope change amount sequence is obtained, and the slope change amount mean sequence is obtained.

[0022] Optionally, in the data analysis module, the tension overall deviation of the target element corresponding time point in the tension slope sequence, the number of historical stretching state time periods in the tension slope sequence, and the mean of the tension overall deviation of each historical stretching state time period are obtained, and specifically include:

[0023] The local tension slope element corresponding to the target abnormal slope change amount is determined from the tension slope sequence, wherein the target abnormal slope change amount is the element corresponding to the minimum timestamp in the abnormal slope change amount sequence.

[0024] The element with the maximum timestamp in the local tension slope element is determined as the boundary element.

[0025] The tension slope sequence is divided according to the boundary element, and the historical stretching state time period is obtained.

[0026] The mean of the elements in the tension slope sequence is obtained, and the slope mean is obtained.

[0027] The difference between the ath element in the tension slope sequence and the slope mean is obtained, and the absolute value of the difference is determined as the tension overall deviation of the target element corresponding time point.

[0028] The tension overall deviation of the target element corresponding time point in the tension slope sequence is obtained, wherein the time point of the target element is the target time.

[0029] According to the number of elements in the abnormal slope change amount sequence, the number of historical stretching state time periods in the tension slope sequence is determined.

[0030] The mean of the tension overall deviation of each historical stretching state time period is calculated.

[0031] Optionally, in the data analysis module, the monotonic tension data segment and the tension distance data segment are obtained according to the state tension data sequence and the state tension distance sequence, and specifically, the method comprises the following steps:

[0032] An extreme point in the slope change amount sequence is obtained, the extreme point is taken as a demarcation point, the slope change amount sequence is segmented, and a monotonic slope change amount data segment is obtained;

[0033] An element corresponding to each element in each monotonic slope change amount data segment in the state tension data sequence is obtained, and a monotonic tension data segment is obtained;

[0034] An element corresponding to each element in each monotonic tension data segment in the state tension distance sequence is obtained, and a tension distance data segment is obtained.

[0035] Optionally, in the data analysis module, the change gap of each monotonic tension data segment and the corresponding tension distance data segment is calculated according to the real stretching degree at the target moment, the monotonic tension data segment and the tension distance data segment, and specifically, the method comprises the following steps:

[0036] The tension slope mean value and the tension slope change amount mean value corresponding to the dth monotonic tension data segment are obtained;

[0037] The distance slope mean value and the distance slope change amount mean value corresponding to the dth tension distance data segment are obtained;

[0038] The change gap of the dth monotonic tension data segment and the dth tension distance data segment is calculated according to the real stretching degree at the target moment, the tension slope mean value corresponding to the dth monotonic tension data segment, the tension slope change amount mean value corresponding to the dth monotonic tension data segment, the distance slope mean value corresponding to the dth tension distance data segment and the distance slope change amount mean value corresponding to the dth tension distance data segment;

[0039] The change gap of each monotonic tension data segment and the corresponding tension distance data segment is obtained.

[0040] Optionally, in the data analysis module, a three-dimensional space coordinate system is constructed, and a three-dimensional coordinate point set is determined according to the monotonic tension data segment and the tension distance data segment, and specifically, the method comprises the following steps:

[0041] The three-dimensional space coordinate system is constructed with the tension slope mean value of the monotonic tension data segment as the x-axis, the distance slope mean value of the tension distance data segment as the y-axis and the change gap as the z-axis;

[0042] The three-dimensional coordinate point of the dth monotonic tension data segment and the dth tension distance data segment is constructed with the tension slope mean value of the dth monotonic tension data segment as the x-axis coordinate, the distance slope mean value of the dth tension distance data segment as the y-axis coordinate and the change gap of the dth monotonic tension data segment and the dth tension distance data segment as the z-axis coordinate.

[0043] Obtain the three-dimensional coordinate points of each monotonic tension data segment and the corresponding tension distance data segment to obtain a three-dimensional coordinate point set.

[0044] Optionally, the data analysis module obtains the transition smoothness of each vector in the three-dimensional space coordinate system, specifically including:

[0045] Obtain the e-th vector and the e+1-th vector in the three-dimensional space coordinate system, wherein the e-th vector is obtained according to the f-th three-dimensional coordinate point and the f+1-th three-dimensional coordinate point in the three-dimensional coordinate point set, and the e+1-th vector is obtained according to the f+1-th three-dimensional coordinate point and the f+2-th three-dimensional coordinate point in the three-dimensional coordinate point set;

[0046] Calculate the degree difference value and the distance difference value of the e-th vector and the e+1-th vector;

[0047] According to the degree difference value and the distance difference value of the e-th vector and the e+1-th vector, the transition smoothness of the e-th vector is calculated.

[0048] Optionally, the data analysis module determines a target vector from the vectors, and calculates the rupture degree at the target time according to the transition smoothness and the change gap of the target vector, specifically including:

[0049] Determine the target vector from the three-dimensional space coordinate system, wherein the absolute value of the difference between the timestamp of the target vector and the target time is the smallest, the timestamp of the target vector is determined according to the timestamp of the three-dimensional coordinate point with the largest timestamp in the three-dimensional coordinate point corresponding to the target vector, and the timestamp of the three-dimensional coordinate point is determined according to the timestamp of the element with the largest timestamp in the tension distance data segment;

[0050] Obtain the transition smoothness of the target vector;

[0051] According to the transition smoothness of the target vector and the change gap of each monotonic tension data segment and the corresponding tension distance data segment, the rupture degree at the target time is calculated.

[0052] The present application provides a kind of special electronic tensile testing machine for non-woven fabric, including as a kind of special electronic tensile testing machine for non-woven fabric tensile test system module.

[0053] The technical scheme of the present application has the following advantages:

[0054] In the embodiment of the present application, by analyzing the interference of the clamping of the electronic tensile testing machine clamp on the non-woven fabric during stretching, the real stretching degree of the non-woven fabric is calculated in real time, the interference of the clamp clamping the non-woven fabric on the tensile force data is reduced, and the maximum value of the tensile force data is more reliable; then the real stretching degree is combined with the tensile distance, the ability range of the internal random unevenly distributed fiber region of the non-woven fabric during stretching is analyzed, and the breaking degree of the electronic tensile testing machine during stretching of the non-woven fabric is calculated in real time, so that the system can be more rapid and accurate when judging whether the non-woven fabric has been broken. The threshold condition of the breaking of the non-woven fabric is more intelligently adjusted, the moment of stopping the operation of the tensile testing machine is more accurate, and the precision of the electronic tensile testing machine for detecting the tensile force of the non-woven fabric is improved. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0056] Figure 1 The structure diagram of a non-woven fabric special electronic tensile testing machine tensile testing system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0057] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the specific implementation, structure, features and effects of a non-woven fabric special electronic tensile testing machine tensile testing system according to the present application are described in detail as follows. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0059] The specific scheme of the non-woven fabric special electronic tensile testing machine tensile testing system provided by the present application is specifically described below with reference to the drawings.

[0060] The present application provides a non-woven fabric special electronic tensile testing machine tensile testing system, please refer to Figure 1 which shows the structure diagram of a non-woven fabric special electronic tensile testing machine tensile testing system provided by an embodiment of the present application, the system comprises:

[0061] The data acquisition module 101 is configured to determine a state tension data sequence and a state tension distance sequence according to tension data and a distance between the clamping pieces of the electronic tension machine at each time point.

[0062] Exemplarily, the non-woven fabric to be detected for tension is clamped in the upper and lower clamping pieces of the electronic tension machine, and after the non-woven fabric is clamped flatly and smoothly, the electronic tension machine is started to obtain tension data and a corresponding distance between the clamping pieces at each time point in real time at a frequency of 4 times per second (a preset value, which can be set according to actual needs). The distance between the clamping pieces is the difference between the distance between the clamping pieces at a certain time point and the distance between the upper and lower clamping pieces before the operation of the electronic tension machine.

[0063] The data analysis module 102 is configured to calculate a tension slope of each element in the state tension data sequence to obtain a tension slope sequence, determine a real stretching degree at a target time according to the tension slope sequence, obtain a monotonic tension data segment and a tension distance data segment according to the state tension data sequence and the state tension distance sequence, calculate a change gap of each monotonic tension data segment and a corresponding tension distance data segment according to the real stretching degree at the target time, the monotonic tension data segment and the tension distance data segment, construct a three-dimensional coordinate system, and determine a three-dimensional coordinate point set according to the monotonic tension data segment and the tension distance data segment, obtain transition smoothness of each vector in the three-dimensional coordinate system, wherein the vector is determined according to a position of an element in the three-dimensional coordinate point set in the three-dimensional coordinate system, and calculate a rupture degree at the target time according to the transition smoothness and the change gap of the target vector.

[0064] In this embodiment, the data analysis module determines the real stretching degree at the target time according to the tension slope sequence, and specifically includes the following steps.

[0065] According to the tension slope sequence, a slope change amount sequence and a slope change amount mean sequence are determined.

[0066] Elements in the slope change amount mean sequence that are less than a preset slope change amount threshold are obtained to obtain an abnormal slope change amount sequence.

[0067] When the number of elements in the abnormal slope change amount sequence is equal to 0, it is determined that the non-woven fabric is in a normal stretching state, and the state tension data sequence and the state tension distance sequence are updated until the number of elements in the abnormal slope change amount sequence is not equal to 0.

[0068] When the number of elements in the abnormal slope change amount sequence is not equal to 0, the tension overall deviation at a target time point corresponding to a target element in the tension slope sequence, the number of historical stretching state time periods in the tension slope sequence, and the mean value of the tension overall deviation of each historical stretching state time period are obtained.

[0069] According to the overall deviation of the target element corresponding to the time point, the number of historical stretching state time periods, and the mean of the overall deviation of the pulling force in each historical stretching state time period, the real stretching degree at the target time is calculated.

[0070] In the data analysis module, according to the pulling force slope sequence, the slope change amount sequence and the slope change amount mean sequence are determined, specifically including:

[0071] The difference between the c+1th element and the cth element in the pulling force slope sequence is determined as the slope change amount of the c+1th element;

[0072] The slope change amount of each element in the pulling force slope sequence is obtained, and the slope change amount sequence is obtained, wherein the c+1th element is not the first element in the pulling force slope sequence;

[0073] The i-th to i+n-th elements in the slope change amount sequence are obtained and the mean is calculated, to obtain the local slope change amount mean of the i-th element, wherein i and n are positive integers;

[0074] The local slope change amount mean of each element in the slope change amount sequence is obtained, and the slope change amount mean sequence is obtained.

[0075] In the data analysis module, the overall deviation of the pulling force corresponding to the time point of the target element in the pulling force slope sequence, the number of historical stretching state time periods in the pulling force slope sequence, and the mean of the overall deviation of the pulling force in each historical stretching state time period are obtained, specifically including:

[0076] The local pulling force slope element corresponding to the target abnormal slope change amount is determined from the pulling force slope sequence, wherein the target abnormal slope change amount is the element corresponding to the minimum timestamp in the abnormal slope change amount sequence;

[0077] The element with the largest timestamp in the local pulling force slope element is determined as the boundary element;

[0078] The pulling force slope sequence is divided according to the boundary element, to obtain the historical stretching state time period;

[0079] The mean of the elements in the pulling force slope sequence is obtained, to obtain the slope mean;

[0080] The difference between the a-th element in the pulling force slope sequence and the slope mean is obtained, and the absolute value of the difference is determined as the overall deviation of the pulling force corresponding to the time point of the a-th element;

[0081] The overall deviation of the pulling force corresponding to the time point of the target element in the pulling force slope sequence is obtained, wherein the time point of the target element is the target time;

[0082] According to the number of elements in the abnormal slope change amount sequence, the number of historical stretching state time periods in the pulling force slope sequence is determined;

[0083] Calculate the average of the overall deviation of the tension force of each historical stretching state time period.

[0084] In the data analysis module, according to the state tension data sequence and the state tension distance sequence, the monotonic tension data segment and the tension distance data segment are obtained, specifically including:

[0085] Obtain the extreme points in the slope change amount sequence, take the extreme points as the demarcation points, segment the slope change amount sequence, and obtain the monotonic slope change amount data segment;

[0086] Obtain the corresponding elements of each element in each monotonic slope change amount data segment in the state tension data sequence to obtain the monotonic tension data segment;

[0087] Obtain the corresponding elements of each element in each monotonic tension data segment in the state tension distance sequence to obtain the tension distance data segment.

[0088] In the data analysis module, according to the real stretching degree of the target moment, the monotonic tension data segment and the tension distance data segment, the change gap of each monotonic tension data segment and the corresponding tension distance data segment is calculated, specifically including:

[0089] Obtain the tension slope mean and the tension slope change amount mean corresponding to the dth monotonic tension data segment;

[0090] Obtain the distance slope mean and the distance slope change amount mean corresponding to the dth tension distance data segment;

[0091] According to the real stretching degree of the target moment, the tension slope mean corresponding to the dth monotonic tension data segment, the tension slope change amount mean corresponding to the dth monotonic tension data segment, the distance slope mean corresponding to the dth tension distance data segment, and the distance slope change amount mean corresponding to the dth tension distance data segment, the change gap of the dth monotonic tension data segment and the dth tension distance data segment is calculated;

[0092] Obtain the change gap of each monotonic tension data segment and the corresponding tension distance data segment.

[0093] In the data analysis module, a three-dimensional space coordinate system is constructed, and a set of three-dimensional coordinate points is determined according to the monotonic tension data segment and the tension distance data segment, specifically including:

[0094] A three-dimensional space coordinate system is constructed with the tension slope mean of the monotonic tension data segment as the x-axis, the distance slope mean of the tension distance data segment as the y-axis, and the change gap as the z-axis;

[0095] The tension slope mean of the dth monotonic tension data segment is taken as the x-axis coordinate, the distance slope mean of the dth tension distance data segment is taken as the y-axis coordinate, and the change gap of the dth monotonic tension data segment and the dth tension distance data segment is taken as the z-axis coordinate to construct a three-dimensional coordinate point of the dth monotonic tension data segment and the dth tension distance data segment.

[0096] The three-dimensional coordinate point of each monotonic tension data segment and the corresponding tension distance data segment is obtained to obtain a three-dimensional coordinate point set.

[0097] A three-dimensional space coordinate system is constructed in the data analysis module, and the three-dimensional coordinate point set is determined according to the monotonic tension data segment and the tension distance data segment, and specifically includes:

[0098] A three-dimensional space coordinate system is constructed with the tension slope mean of the monotonic tension data segment as the x-axis, the distance slope mean of the tension distance data segment as the y-axis, and the change gap as the z-axis.

[0099] The tension slope mean of the dth monotonic tension data segment is taken as the x-axis coordinate, the distance slope mean of the dth tension distance data segment is taken as the y-axis coordinate, and the change gap of the dth monotonic tension data segment and the dth tension distance data segment is taken as the z-axis coordinate to construct a three-dimensional coordinate point of the dth monotonic tension data segment and the dth tension distance data segment.

[0100] The three-dimensional coordinate point of each monotonic tension data segment and the corresponding tension distance data segment is obtained to obtain a three-dimensional coordinate point set.

[0101] A target vector is determined from the vector in the data analysis module, and the rupture degree of the target time is calculated according to the transition smoothness and the change gap of the target vector, and specifically includes:

[0102] The target vector is determined from the three-dimensional space coordinate system, wherein the absolute value of the difference between the timestamp of the target vector and the target time is the smallest, the timestamp of the target vector is determined according to the timestamp of the three-dimensional coordinate point with the largest timestamp in the three-dimensional coordinate point corresponding to the target vector, and the timestamp of the three-dimensional coordinate point is determined according to the timestamp of the element with the largest timestamp in the tension distance data segment;

[0103] The transition smoothness of the target vector is obtained;

[0104] The rupture degree of the target time is calculated according to the transition smoothness of the target vector and the change gap of each monotonic tension data segment and the corresponding tension distance data segment.

[0105] Exemplarily, in the prior art, when a non-woven fabric is tested by using an electronic tensile testing machine, a computer system connected to the tensile testing machine updates the highest peak value of the detected tension in real time, and determines whether the tension data at the current time decays to 50% (default value) of the highest peak value. If so, the system defaults that the non-woven fabric has been broken at this time, and the tensile testing machine stops working.

[0106] In actual scenarios, however, in order to save costs and improve efficiency, the same electronic tensile testing machine is used to test multiple non-woven fabrics. The structures of fiber materials and external forces in the forming process are different between different types of non-woven fabrics, resulting in certain differences in fiber distribution between different types of non-woven fabrics. Influenced by the manufacturing process of the non-woven fabric, even the non-woven fabrics produced in different batches of the same type will have different tensile capacities due to the randomness of fiber distribution. When the electronic tensile testing machine stretches the non-woven fabric, if the non-woven fabric is broken, a significant distance fluctuation will occur. In summary, the present embodiment combines tension data and tension distance to analyze abnormal information caused by the breakage of the non-woven fabric in real time when the electronic tensile testing machine tests the non-woven fabric, and calculates the breakage degree of the non-woven fabric stretched by the electronic tensile testing machine in real time according to the abnormal information.

[0107] In the actual non-woven fabric tension test process, the fixture of the electronic tensile testing machine fixes the non-woven fabric only once (i.e., before the tension test, the non-woven fabric is fixed by manually adjusting the fixture, and the fixation of the non-woven fabric will not be adjusted subsequently), so the clamping action of the fixture on the non-woven fabric is interfered by a certain human factor: if the fixture clamps the non-woven fabric loosely, then when the non-woven fabric is stretched, the non-woven fabric at one end may gradually come off the fixture; if the fixture clamps the non-woven fabric tightly, then when the non-woven fabric is stretched, the non-woven fabric at one end may be subjected to a relatively large pressure, thereby causing damage to the nearby area. At this time, the damage is human-induced damage and cannot truly represent the stretching quality of the non-woven fabric.

[0108] The above two interference conditions will cause the tension data to have a change state of continuously rising and then suddenly and greatly falling (the change state of the tension data when damage occurs during conventional tension testing is also this state), thereby confusing the case when the non-woven fabric is actually damaged. In addition, the actual change process of the tension data in the above two interference conditions is different from the change process of the tension data during conventional tension testing, so the real process of the deformation of the non-woven fabric when the non-woven fabric is stretched by the electronic tensile testing machine can be analyzed according to the tension data, the interference factor of the fixture clamping can be excluded, and the real stretching degree of the non-woven fabric can be calculated in real time.

[0109] Therefore, taking the current time as the target time, if the clamp is not clamped properly (too loose or too tight), the overall change in the tension detected by the clamp when the non-woven fabric is stretched will be slower or faster, thereby causing the tension change to deviate from the normal overall change state. Therefore, the data analysis steps are as follows:

[0110] The tension slope of each element in the state tension data sequence is obtained to obtain a tension slope sequence. The tension slope can be determined by the ratio of the difference between the two adjacent elements in the state tension data sequence (the latter element minus the former element) to the time interval (for example, if the collection frequency is 4 times per second, the time interval is 1 / 4 second).

[0111] The slope change amount sequence and the slope change amount mean sequence are obtained:

[0112] The slope change amount sequence is obtained by subtracting the former element from the latter element of the two adjacent elements in the tension slope sequence, and taking the difference as the slope change amount.

[0113] The slope change amount mean sequence is a local slope change amount mean in this embodiment. Alternatively, a sliding window with a length of n (a preset value) and a step of 1 can be used to start sliding through the slope change amount sequence from the first element, and the slope change amount mean of the sliding window at each traversal is calculated to obtain the slope change amount mean sequence. The elements in the slope change amount mean sequence that are less than the preset slope change amount threshold are obtained to obtain an abnormal slope change amount sequence.

[0114] When there are elements in the abnormal slope change amount sequence, it indicates that the stretching of the non-woven fabric has exceeded the yield point of the non-woven fabric, and at this time the non-woven fabric is more likely to deform or break. When there are no elements in the abnormal slope change amount sequence, it indicates that the stretching of the non-woven fabric has not exceeded the yield point of the non-woven fabric, and the non-woven fabric can continue to be tested for stretching. The yield point refers to the turning point at which the material begins to irreversibly deform (permanently deform) when the stress reaches a certain critical value during the stretching process of the non-woven fabric.

[0115] Alternatively, the preset slope change amount threshold can be set to 0.55 in a preferred embodiment. The size of the preset slope change amount threshold can be set according to the actual situation, and no specific numerical limit is given here.

[0116] Determine the local tensile slope element corresponding to the target abnormal slope change amount in the tensile slope sequence, wherein the time interval composed of the time stamps of all elements in the local tensile slope element is the time period in which the yield point of the non-woven fabric is located, and the element with the maximum time in the time period is determined as the yield point, that is, the dividing element. According to the dividing element, the tensile slope sequence can be divided to obtain the historical stretching state time period, wherein the historical stretching state time period includes a fast stretching time period and a slow stretching time period, and the tensile slope sequence before the yield point is the fast stretching time period, and the tensile slope sequence after the yield point is the slow stretching time period.

[0117] It should be noted that if there is a yield point before the current time, the tensile slope sequence before the yield point can be considered as a fast stretching time period, and the tensile slope sequence after the yield point is a slow stretching time period.

[0118] In the present embodiment, both the fast stretching time period and the slow stretching time period are regarded as a historical stretching state time period, therefore, the number of historical stretching state time periods in the tensile slope sequence can only be 1 or 2.

[0119] According to the tensile overall deviation degree of the target element corresponding time point, the number of historical stretching state time periods and the mean value of the tensile overall deviation degree of each historical stretching state time period, the real stretching degree of the target time is calculated, and the calculation formula can be:

[0120]

[0121] Wherein, represents the real stretching degree of the target time, represents the tensile overall deviation degree of the target element corresponding time point, represents the number of historical stretching state time periods, represents the mean value of the tensile overall deviation degree of the first historical stretching state time period, represents the natural exponential function.

[0122] If the real stretching degree is larger, it means that when the electronic tensile testing machine stretches the non-woven fabric to the current time, the non-woven fabric receives the interference force generated by the improper clamp, and the interference force is weaker, which reflects that the tensile data detected by the electronic tensile testing machine at the current time is more real and reliable, and the highest value of the generated tensile data is more in line with the real demand.

[0123] Compared with the traditional woven cloth, the fibers inside the non-woven fabric are randomly formed, and there are local areas with relatively dense fiber structure and relatively loose fiber structure, and these local areas are randomly distributed in the non-woven fabric sample to be detected, so that the fiber surface inside the non-woven fabric has a relatively obvious uneven distribution state. When the electronic tensile testing machine stretches the non-woven fabric sample up and down, the whole non-woven fabric will be subjected to the tension generated by the displacement of the upper and lower clamps, so that the local areas will be subjected to different deformation changes: the local areas with relatively loose fiber structure (weak tensile resistance) will be the first to produce obvious deformation when the non-woven fabric is stretched, and then the local areas with relatively dense fiber structure (strong tensile resistance) will be the second. With the continuous driving of the electronic tensile testing machine, the distance between the upper and lower clamps increases, and the non-woven fabric gradually reaches the stretching limit. Therefore, the real stretching degree and the tension distance can be combined to analyze the ability range of the randomly unevenly distributed fiber areas inside the non-woven fabric to withstand stretching during the stretching process, and the breaking degree of the electronic tensile testing machine when stretching the non-woven fabric can be calculated in real time.

[0124] Taking the state tension data sequence and the state tension distance sequence at the current moment as an example, the slope change amount sequence is segmented according to the extreme points to obtain a monotonous slope change amount data segment. Since the slope change amount sequence is calculated from the state tension data sequence, each element in the monotonous slope change amount data segment corresponds to a number of elements in the state tension data sequence. According to the correspondence between each element in the monotonous slope change amount data segment and the elements in the state tension data sequence, the state tension data sequence is segmented to obtain a monotonous tension data segment. Correspondingly, each element in the state tension data sequence also corresponds to an element in the state tension distance sequence, and according to the correspondence, the state tension distance sequence is also segmented to obtain a tension distance data segment.

[0125] Taking any one monotonous tension data segment and the corresponding tension distance data segment as an example, the tension slope mean value and the distance slope mean value of the monotonous tension data segment and the corresponding tension distance data segment are obtained. The tension slope change amount mean value and the distance slope change amount mean value

[0126] of the monotonous tension data segment and the corresponding tension distance data segment are obtained.

[0127] wherein, The change gap represents the change gap. The greater the change gap, the weaker the synchronous change caused by the change of the respective data of the monotonic tension data segment and the tension distance data segment, and the greater the degree of non-woven fabric internal fiber stretch resistance.

[0128] Limited by the limitations of the tension machine test, the data that can be directly observed is mainly the tension data and the tension distance. In the actual scene, the local over-dense and local over-dense conditions of the non-woven fabric fibers mainly affect the change relationship of the tension data and the tension distance. Therefore, in order to quantify the local over-dense and local over-dense conditions of the non-woven fabric fibers, a three-dimensional space coordinate system is constructed, and the change degree of the tension data and the tension distance is taken as the reference axis in the space. On this basis, the difference fluctuation relationship between the changes is added as a new reference axis, and the three-dimensional space distribution constructed by these reference axes makes the local over-dense and local over-dense conditions of the non-woven fabric fibers quantifiable:

[0129] A three-dimensional space coordinate system is constructed with the average tension slope of the monotonic tension data segment as the x-axis, the average distance slope of the tension distance data segment as the y-axis, and the change gap as the z-axis. And the average tension slope of the dth monotonic tension data segment is taken as the x-axis coordinate, the average distance slope of the dth tension distance data segment is taken as the y-axis coordinate, and the change gap of the dth monotonic tension data segment and the dth tension distance data segment is taken as the z-axis coordinate. The three-dimensional coordinate point of the dth monotonic tension data segment and the dth tension distance data segment is constructed. The three-dimensional coordinate point is represented in the space coordinate system, and each three-dimensional coordinate point corresponds to a monotonic tension data segment and a tension distance data segment.

[0130] According to the timestamp of each three-dimensional coordinate point, the timestamp of the element with the maximum timestamp in the tension distance data segment. Connect the adjacent three-dimensional coordinate points on the timestamp to construct a vector, and determine the target vector from the vector. The target vector is the vector closest to the target time in the timestamp. Get the transition smoothness of the target vector. The calculation formula of the transition smoothness of the target vector can be:

[0131]

[0132] Wherein, represents the transition smoothness, represents the degree difference value of the included angle of the target vector and the included angle of the adjacent vector, represents the distance difference value of the modulus between the target vector and the adjacent vector . The greater the transition smoothness, the weaker the fluctuation caused by the transition of adjacent monotonic tension data segments, and the closer the originally weak fiber structure area in the non-woven fabric to the stretching limit (so the fiber structure weak area must be damaged during stretching).

[0133] The included angle of the target vector represents an included angle formed by the target vector and an adjacent vector, the included angle of the adjacent vector represents an included angle formed by the adjacent vector and another adjacent vector, and the other adjacent vector is a vector adjacent to the adjacent vector and excluding the target vector.

[0134] According to the transition smoothness of the target vector and the change gap between each monotonic tension data segment and the corresponding tension distance data segment, the rupture degree of the target moment is calculated, and the calculation formula is:

[0135]

[0136] Among them, represents the rupture degree, represents the change gap between the monotonic tension data segment and the corresponding tension distance data segment, represents the number of monotonic tension data segments existing at the target moment, represents a normalization function. The greater the rupture degree, the more tension is required to move the clamp when the non-woven fabric is continuously stretched to the current moment, reflecting that the internal fibers of the non-woven fabric are stretched to the limit, and the time point of damage is closer.

[0137] The data adjustment module 103 is configured to adjust the running termination condition of the electronic tension machine according to the rupture degree of the target moment.

[0138] For example, in the embodiment, the running termination condition of the electronic tension machine is adjusted. When the tension value of the target moment is reduced to a preset proportion of the maximum tension value , the electronic tension machine stops running.

[0139] Therefore, the adjustment mode can be: when the rupture degree of the target moment is greater than a preset rupture degree threshold, the time length between the target moment and the first moment in the slow stretching time period is obtained , and after normalization , the adjustment weight is calculated.

[0140] If is greater than a preset time length threshold, it means that the tension machine has stretched for a long enough time to reach the limit, indicating that the internal fiber of the non-woven fabric sample detected this time has fewer or no weak areas, and the tension decreases less obviously when the actual fracture occurs. Therefore, the preset proportion of the maximum tension value needs to be adjusted upwards, and the preset proportion of the maximum tension value is adjusted to .

[0141] If​ Less than or equal to the preset time length threshold, it means that the tensile testing machine is stretched for a very short time to reach the limit, which means that the non-woven fabric sample has less or no thin and thick areas inside, and the more obvious the tensile force drops when the real fracture occurs, therefore, the preset proportion of the maximum tensile force value is adjusted downward. The preset proportion of the maximum tensile force value .

[0142] When the target time is less than or equal to the preset breaking degree threshold, the preset proportion of the maximum tensile force value is not adjusted.

[0143] Optionally, the preset proportion of the maximum tensile force value , the preset breaking degree threshold and the preset time length threshold in the embodiment can be adjusted according to the actual situation, and no specific numerical limit is made here, in a preferred embodiment, the preset proportion of the maximum tensile force value , the preset breaking degree threshold and the preset time length threshold can be set to 50%, 0.75 and 0.5 respectively.

[0144] And in the stretching process of each non-woven fabric, the preset proportion of the maximum tensile force value is adjusted only once.

[0145] The application also provides a special electronic tensile testing machine for non-woven fabric, which comprises a module of the special electronic tensile testing machine for non-woven fabric.

[0146] It should be noted that the above-mentioned sequence of the embodiments of the application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or may be advantageous.

[0147] Each embodiment in the specification is described in a progressive manner, and the same and similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the differences from other embodiments.

[0148] The above only describes the preferred embodiments of the application, and does not limit the application, any modification, equivalent replacement, improvement, etc. made within the principles of the application shall be included in the protection scope of the application.

Claims

1. A tensile testing system for a nonwoven fabric-specific electronic tensile testing machine, characterized in that, The tensile testing system includes: The data acquisition module is used to determine the state tensile data sequence and the state tensile distance sequence based on the tensile data and clamp distance of the electronic tensile testing machine at each time point. The data analysis module is used to calculate the tensile slope of each element in the state tensile data sequence, obtaining a tensile slope sequence; determine the actual tensile degree at the target time based on the tensile slope sequence; obtain monotonic tensile data segments and tensile distance data segments based on the state tensile data sequence and state tensile distance data sequence; calculate the variation difference between each monotonic tensile data segment and its corresponding tensile distance data segment based on the actual tensile degree at the target time, the monotonic tensile data segments, and the tensile distance data segments; construct a three-dimensional spatial coordinate system and determine the set of three-dimensional coordinate points based on the monotonic tensile data segments and tensile distance data segments; obtain the transition smoothness of each vector in the three-dimensional spatial coordinate system, where the vector is determined based on the position of the elements in the three-dimensional coordinate point set in the three-dimensional spatial coordinate system; determine the target vector from the vectors, and calculate the degree of fracture at the target time based on the transition smoothness and variation difference of the target vector; The data adjustment module is used to adjust the termination conditions of the electronic tensile testing machine according to the degree of fracture at the target time.

2. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 1, characterized in that, The data analysis module determines the actual degree of tension at the target time based on the tensile slope sequence, specifically including: Based on the tensile slope sequence, determine the slope change sequence and the mean slope change sequence; Obtain elements in the mean slope change sequence that are less than a preset slope change threshold to obtain the abnormal slope change sequence. When the number of elements in the abnormal slope change sequence is equal to 0, it is determined that the nonwoven fabric is in a normal tensile state, and the state tensile data sequence and state tensile distance sequence are updated until the number of elements in the abnormal slope change sequence is not equal to 0. When the number of elements in the abnormal slope change sequence is not equal to 0, obtain the overall deviation of the tension at the time point corresponding to the target element in the tension slope sequence, the number of historical tension state time periods in the tension slope sequence, and the average value of the overall deviation of the tension for each historical tension state time period. The actual degree of stretching at the target time is calculated based on the overall deviation of the tensile force at the corresponding time point of the target element, the number of historical stretching state time periods, and the average of the overall deviation of the tensile force in each historical stretching state time period.

3. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 2, characterized in that, The data analysis module determines the slope change sequence and the mean slope change sequence based on the tensile slope sequence, specifically including: The difference between the (c+1)th element and the cth element in the tensile slope sequence is determined as the slope change of the (c+1)th element. Obtain the slope change of each element in the tension slope sequence to obtain the slope change sequence, where the (c+1)th element is not the first element in the tension slope sequence; Obtain the i-th to i+n-th elements in the slope change sequence and calculate the mean to obtain the mean local slope change of the i-th element, where i and n are positive integers; Obtain the mean local slope change of each element in the slope change sequence to obtain the mean slope change sequence.

4. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 2, characterized in that, The data analysis module obtains the overall tensile deviation at the time point corresponding to the target element in the tensile slope sequence, the number of historical tensile state time periods in the tensile slope sequence, and the average value of the overall tensile deviation for each historical tensile state time period, specifically including: Determine the local tensile slope element corresponding to the target abnormal slope change from the tensile slope sequence, where the target abnormal slope change is the element corresponding to the smallest timestamp in the abnormal slope change sequence; The element with the largest timestamp among the local tensile slope elements is determined as the boundary element; The tensile slope sequence is divided according to the boundary elements to obtain the time period of historical tensile state; Obtain the mean of the elements in the tension slope sequence to get the mean slope; Obtain the difference between the a-th element in the tension slope sequence and the mean slope, and determine the absolute value of the difference as the overall tension deviation at the time point corresponding to the a-th element; Obtain the overall deviation of the tensile force at the time point corresponding to the target element in the tensile slope sequence, where the time point of the target element is the target time. Based on the number of elements in the abnormal slope change sequence, determine the number of historical tensile state time periods in the tensile slope sequence; Calculate the mean of the overall deviation of tensile force for each historical tensile state time period.

5. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 1, characterized in that, The data analysis module obtains monotonic tension data segments and tension distance data segments based on the state tension data sequence and the state tension distance sequence, specifically including: Obtain the extreme points in the slope change sequence, use the extreme points as dividing points, and segment the slope change sequence to obtain monotonic slope change data segments. Obtain the element corresponding to each element in the state tension data sequence in each monotonic slope change data segment to obtain the monotonic tension data segment; Obtain the element corresponding to each element in the state tension distance sequence in each monotonic tension data segment to obtain the tension distance data segment.

6. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 1, characterized in that, The data analysis module calculates the variation difference between each monotonic tensile data segment and its corresponding tensile distance data segment based on the actual stretching degree at the target time, the monotonic tensile force data segment, and the tensile distance data segment. Specifically, this includes: Obtain the mean value of the tension slope and the mean value of the change in tension slope corresponding to the d-th monotonic tension data segment; Obtain the mean distance slope and the mean change in distance slope corresponding to the d-th tension distance data segment; Based on the actual stretching degree at the target time, the mean of the tension slope corresponding to the dth monotonic tension data segment, the mean of the change in the tension slope corresponding to the dth monotonic tension data segment, the mean of the distance slope corresponding to the dth tension distance data segment, and the mean of the change in the distance slope corresponding to the dth tension distance data segment, calculate the difference in change between the dth monotonic tension data segment and the dth tension distance data segment; Obtain the variation difference between each monotonic tensile force data segment and the corresponding tensile distance data segment.

7. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 1, characterized in that, The data analysis module constructs a three-dimensional spatial coordinate system and determines a set of three-dimensional coordinate points based on monotonic tension data segments and tension distance data segments, specifically including: A three-dimensional spatial coordinate system is constructed with the mean slope of the monotonic tensile force data segment as the x-axis, the mean slope of the tensile distance data segment as the y-axis, and the variation difference as the z-axis. Using the mean slope of the dth monotonic tension data segment as the x-axis coordinate, the mean slope of the dth tension distance data segment as the y-axis coordinate, and the difference in variation between the dth monotonic tension data segment and the dth tension distance data segment as the z-axis coordinate, construct the three-dimensional coordinate points of the dth monotonic tension data segment and the dth tension distance data segment; Obtain the three-dimensional coordinate points of each monotonic tensile force data segment and the corresponding tensile distance data segment to obtain a set of three-dimensional coordinate points.

8. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 1, characterized in that, The data analysis module obtains the transition smoothness of each vector in the three-dimensional coordinate system, specifically including: Obtain the e-th vector and the (e+1)-th vector in the three-dimensional coordinate system, where the e-th vector is obtained from the f-th and (f+1)-th three-dimensional coordinate points in the set of three-dimensional coordinate points, and the (e+1)-th vector is obtained from the (f+1)-th and (f+2)-th three-dimensional coordinate points in the set of three-dimensional coordinate points. Calculate the degree difference and distance difference between the e-th vector and the (e+1)-th vector; The transition smoothness of the e-th vector is calculated based on the degree difference and distance difference between the e-th vector and the (e+1)-th vector.

9. The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine according to claim 1, characterized in that, The data analysis module determines the target vector from the vectors, and calculates the degree of rupture at the target time based on the transition smoothness and change gap of the target vector, specifically including: The target vector is determined from the three-dimensional spatial coordinate system, where the absolute value of the difference between the timestamp of the target vector and the target time is the smallest. The timestamp of the target vector is determined based on the timestamp of the three-dimensional coordinate point with the largest timestamp among the three-dimensional coordinate points corresponding to the target vector. The timestamp of the three-dimensional coordinate point is determined based on the timestamp of the element with the largest timestamp in the tension distance data segment. Obtain the transition smoothness of the target vector; The degree of fracture at the target moment is calculated based on the smoothness of the transition of the target vector and the difference in variation between each monotonic tensile data segment and the corresponding tensile distance data segment.

10. A special electronic tensile testing machine for nonwoven fabrics, characterized in that, Including a tensile testing system for a nonwoven fabric-specific electronic tensile testing machine as described in any one of claims 1-9.

Images