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

Abstract

The present application relates to the field of tension test, specifically relates to a kind of electronic tensile testing machine and tensile testing system special for non-woven fabric, comprising: data acquisition module, for determining state tension data sequence and state tension distance sequence;Data analysis module, for calculating tension slope sequence;Determine the true degree of stretching of target time;Obtain monotonic tension data segment and tension distance data segment;Calculate the change gap of each monotonic tension data segment and corresponding tension distance data segment;Construct three-dimensional space coordinate system, determine three-dimensional coordinate point set;Obtain the transition smoothness of each vector in three-dimensional space coordinate system;Determine target vector from vector, calculate the rupture degree of target time;Data adjustment module, for adjusting the running termination condition of electronic tensile testing machine according to the rupture degree of target time.The present application can improve the precision of electronic tensile testing machine for non-woven fabric tensile test.

Description

Technical Field

[0001] This invention relates to the field of tension testing, specifically to an electronic tensile testing machine and system for nonwoven fabrics. Background Technology

[0002] Cables are widely used in the transmission of current in various electrical devices. During current transmission, cables are subject to long-term corrosion and wear from the external environment. To address this daily wear and tear, current technology involves wrapping the cable with one or more layers of fabric material for protection. The main materials currently used for wrapping include woven tape, PVC tape, fiberglass tape, and non-woven fabric. Among these, non-woven fabric is primarily used for cable protection due to its excellent overall performance in terms of flexibility (superior to fiberglass tape), breathability (superior to PVC tape), insulation, and temperature resistance (superior to woven tape).

[0003] Nonwoven fabric is a sheet-like material formed by directly binding polymers and fibrous materials (such as short fibers and filaments) together using physical, chemical, or mechanical methods to create a soft, porous, three-dimensional structure. Unlike traditional woven fabrics, the fibers in nonwoven fabrics are mainly randomly formed, and their internal density, thickness, and fiber distribution are not uniform. Therefore, after nonwoven fabric production, an electronic tensile testing machine is typically used to test its tensile strength. The magnitude of the tensile force required to cause breakage is used to determine whether there are quality problems with the nonwoven fabric.

[0004] In existing technologies, when using an electronic tensile testing machine to test the tensile strength of nonwoven fabrics, the computer system connected to the machine updates the peak value of the detected tensile force in real time. When the tensile force decreases to 50% of the peak value (the default percentage), the system assumes that the nonwoven fabric has broken and stops the machine. However, in real-world scenarios, due to the uneven distribution of nonwoven fabric materials and internal fibers, the actual tensile force at which the nonwoven fabric breaks may not be 50% of the peak value (it may be greater than 50% or less than 50%), resulting in low accuracy for the electronic tensile testing machine in detecting the tensile strength of nonwoven fabrics. Summary of the Invention

[0005] This invention provides a dedicated electronic tensile testing machine and tensile testing system for nonwoven fabrics to solve existing problems.

[0006] The tensile testing system for a nonwoven fabric-specific electronic tensile testing machine of the present invention adopts the following technical solution:

[0007] One embodiment of the present invention provides a tensile testing system for a nonwoven fabric-specific electronic tensile testing machine, the tensile testing system comprising:

[0008] 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.

[0009] 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;

[0010] 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.

[0011] Optionally, the data analysis module determines the actual degree of tension at the target time based on the tensile slope sequence, specifically including:

[0012] Based on the tensile slope sequence, determine the slope change sequence and the mean slope change sequence;

[0013] Obtain elements in the mean slope change sequence that are less than a preset slope change threshold to obtain the abnormal slope change sequence.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] Optionally, the data analysis module determines the slope change sequence and the mean slope change sequence based on the tension slope sequence, specifically including:

[0018] 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.

[0019] 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;

[0020] 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;

[0021] Obtain the mean local slope change of each element in the slope change sequence to obtain the mean slope change sequence.

[0022] Optionally, 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 overall tensile deviation for each historical tensile state time period, specifically including:

[0023] 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;

[0024] The element with the largest timestamp among the local tensile slope elements is determined as the boundary element;

[0025] The tensile slope sequence is divided according to the boundary elements to obtain the time period of historical tensile state;

[0026] Obtain the mean of the elements in the tension slope sequence to get the mean slope;

[0027] 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;

[0028] 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.

[0029] 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;

[0030] Calculate the mean of the overall deviation of tensile force for each historical tensile state time period.

[0031] Optionally, 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:

[0032] 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.

[0033] 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;

[0034] 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.

[0035] Optionally, 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:

[0036] 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;

[0037] Obtain the mean distance slope and the mean change in distance slope corresponding to the d-th tension distance data segment;

[0038] 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;

[0039] Obtain the variation difference between each monotonic tensile force data segment and the corresponding tensile distance data segment.

[0040] Optionally, the data analysis module constructs a three-dimensional spatial coordinate system and determines a set of three-dimensional coordinate points based on the monotonic tensile force data segment and the tensile distance data segment, specifically including:

[0041] 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.

[0042] 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;

[0043] 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.

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

[0045] 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.

[0046] Calculate the degree difference and distance difference between the e-th vector and the (e+1)-th vector;

[0047] 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.

[0048] Optionally, 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:

[0049] 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.

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

[0051] 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.

[0052] This invention proposes a special electronic tensile testing machine for nonwoven fabrics, including modules such as a tensile testing system for a special electronic tensile testing machine for nonwoven fabrics.

[0053] The beneficial effects of the technical solution of the present invention are:

[0054] In this embodiment of the invention, by analyzing the interference caused by the clamping of the electronic tensile testing machine on the nonwoven fabric during stretching, the true degree of stretching of the nonwoven fabric is calculated in real time. This reduces the interference of the clamping on the tensile data, making the highest value of the tensile data more reliable. Then, by combining the true degree of stretching with the tensile distance, the tensile capacity range of the randomly and unevenly distributed fiber regions inside the nonwoven fabric during stretching is analyzed. The degree of breakage when the electronic tensile testing machine stretches the nonwoven fabric is calculated in real time, allowing the system to determine whether the nonwoven fabric has broken more quickly and accurately. The threshold condition for nonwoven fabric breakage is adjusted more intelligently, making the timing of the tensile testing machine's stop more accurate and improving the accuracy of the electronic tensile testing machine's tensile strength detection of nonwoven fabric. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a structural diagram of a tensile testing system for a nonwoven fabric-specific electronic tensile testing machine, provided in one embodiment of the present invention. Detailed Implementation

[0057] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a nonwoven fabric-specific electronic tensile testing system proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, 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 this invention pertains.

[0059] The following description, in conjunction with the accompanying drawings, details the specific scheme of the electronic tensile testing system for nonwoven fabrics provided by this invention.

[0060] This invention provides a tensile testing system for a dedicated electronic tensile testing machine for nonwoven fabrics. Please refer to [link / reference]. Figure 1 The diagram illustrates a structural diagram of a tensile testing system for nonwoven fabrics provided in an embodiment of the present invention. The system includes:

[0061] The data acquisition module 101 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.

[0062] For example, the nonwoven fabric to be tested for tensile strength is clamped between the upper and lower clamps of an electronic tensile testing machine. After ensuring that the nonwoven fabric is clamped flat and smoothly, the electronic tensile testing machine is started, acquiring the tensile strength data and the corresponding clamp distance at each time point in real time at a frequency of 4 times / second (preset value, which can be set according to actual needs). The clamp distance is the difference between the clamp distance at a certain time point and the distance between the upper and lower clamps before the electronic tensile testing machine is running.

[0063] The data analysis module 102 is used to calculate the tensile slope of each element in the state tensile data sequence to obtain 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 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 a 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.

[0064] In this embodiment, the data analysis module determines the actual degree of tension at the target time based on the tensile slope sequence, specifically including:

[0065] Based on the tensile slope sequence, determine the slope change sequence and the mean slope change sequence;

[0066] Obtain elements in the mean slope change sequence that are less than a preset slope change threshold to obtain the abnormal slope change sequence.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] The data analysis module determines the slope change sequence and the mean slope change sequence based on the tensile slope sequence, specifically including:

[0071] 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.

[0072] 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;

[0073] 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;

[0074] Obtain the mean local slope change of each element in the slope change sequence to obtain the mean slope change sequence.

[0075] 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 overall tensile deviation for each historical tensile state time period. Specifically, this includes:

[0076] 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;

[0077] The element with the largest timestamp among the local tensile slope elements is determined as the boundary element;

[0078] The tensile slope sequence is divided according to the boundary elements to obtain the time period of historical tensile state;

[0079] Obtain the mean of the elements in the tension slope sequence to get the mean slope;

[0080] 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;

[0081] 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.

[0082] 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;

[0083] Calculate the mean of the overall deviation of tensile force for each historical tensile state time period.

[0084] The data analysis module obtains monotonic tension data segments and tension distance data segments based on the state tension data sequence and state tension distance sequence, specifically including:

[0085] 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.

[0086] 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;

[0087] 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.

[0088] 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:

[0089] 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;

[0090] Obtain the mean distance slope and the mean change in distance slope corresponding to the d-th tension distance data segment;

[0091] 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;

[0092] Obtain the variation difference between each monotonic tensile force data segment and the corresponding tensile distance data segment.

[0093] The data analysis module constructs a three-dimensional spatial coordinate system and determines the set of three-dimensional coordinate points based on the monotonic tensile force data segment and the tensile distance data segment, specifically including:

[0094] 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.

[0095] 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;

[0096] 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.

[0097] The data analysis module constructs a three-dimensional spatial coordinate system and determines the set of three-dimensional coordinate points based on the monotonic tensile force data segment and the tensile distance data segment, specifically including:

[0098] 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.

[0099] 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;

[0100] 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.

[0101] The data analysis module determines the target vector from the vectors, and calculates the degree of rupture at the target time based on the smoothness of the transition and the difference in change of the target vector. Specifically, this includes:

[0102] 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.

[0103] Obtain the transition smoothness of the target vector;

[0104] 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.

[0105] For example, in the prior art, when using an electronic tensile testing machine to perform tensile testing on nonwoven fabrics, the computer system connected to the tensile testing machine updates the highest peak value of the detected tensile force in real time and determines in real time whether the tensile force data at the current moment has decayed to 50% of the highest peak value (default value). If so, the system will assume that the nonwoven fabric has already broken and stop the tensile testing machine from operating.

[0106] In practical applications, to save costs and improve efficiency, the same electronic tensile testing machine is often used to test the tensile strength of various nonwoven fabrics. However, the different fiber structures and external forces during the forming process of different types of nonwoven fabrics result in variations in fiber distribution. Due to the manufacturing process, even nonwoven fabrics of the same type produced in different batches will exhibit different tensile strengths due to the randomness of their fiber distribution. When the electronic tensile testing machine stretches the nonwoven fabric, significant distance fluctuations will occur if the fabric tears. Therefore, this embodiment combines tensile data and tensile distance to analyze in real-time the abnormal information generated by nonwoven fabric tearing during electronic tensile testing, and calculates the degree of tearing during the stretching process based on this abnormal information.

[0107] In actual nonwoven fabric tensile testing, the clamps of the electronic tensile testing machine fix the nonwoven fabric only once (i.e., before the tensile test, the nonwoven fabric is only clamped and fixed by manual adjustment of the clamps, and the fixation of the nonwoven fabric will not be adjusted again afterward). Therefore, the clamping effect of the clamps on the nonwoven fabric is subject to certain human interference: if the clamps hold the nonwoven fabric too loosely, then one end of the nonwoven fabric may gradually detach from the clamps when it is stretched; if the clamps hold the nonwoven fabric too tightly, then one end of the nonwoven fabric may be subjected to greater pressure when it is stretched, thereby causing damage in the nearby area. This damage is damage caused by human intervention and cannot truly represent the tensile quality of the nonwoven fabric.

[0108] Both of these interference scenarios can cause the tensile data to exhibit a continuous increase followed by a sudden, sharp drop (similar to the tensile data changes during conventional tensile testing when damage occurs), thus obscuring the actual damage to the nonwoven fabric. Furthermore, because the actual tensile data changes under these two interference scenarios differ from those during conventional tensile testing, it is possible to analyze the actual deformation process of the nonwoven fabric during stretching using an electronic tensile testing machine, eliminate clamping interference, and calculate the true degree of stretching of the nonwoven fabric in real time.

[0109] Therefore, taking the current moment as the target moment, if the clamp is improperly held (too loose or too tight), the overall change in tension detected by the clamp when the nonwoven fabric is stretched will be slower or faster, thus causing the tension change to deviate from the normal overall change state. Therefore, the data analysis steps are as follows:

[0110] Obtain the tension slope of each element in the state tension data sequence to obtain a tension slope sequence. The tension slope can be determined by subtracting the preceding element from the following two adjacent elements in the state tension data sequence, and then dividing the difference by the time interval (e.g., 1 / 4 second if the sampling frequency is 4 times / second). Optionally, the tension slope at the first moment can be preset to 1, or the tension slope at the first moment can be ignored.

[0111] Obtain the sequence of slope changes and the sequence of the mean of slope changes:

[0112] The slope change sequence is obtained by subtracting the previous element from the next element in the tensile slope sequence, and using the difference as the slope change.

[0113] In this embodiment, the mean sequence of slope changes is a local mean of slope changes. Alternatively, a sliding window of length n (a preset value) with a step size of 1 can be used. Starting from the first element, the window slides through the slope change sequence, calculating the mean of slope change during each iteration. This yields a sequence of average slope changes. Elements in this sequence that are less than a preset slope change threshold are then identified as abnormal slope changes.

[0114] When an element is present in the sequence of abnormal slope changes, it indicates that the tension of the nonwoven fabric has exceeded its yield point, making it more susceptible to deformation or breakage. Conversely, when no element is present in the sequence, it indicates that the tension of the nonwoven fabric has not yet exceeded its yield point, and tensile testing can continue. The yield point refers to the turning point where, during tensile testing, the stress reaches a certain critical value, and the material begins to undergo irreversible plastic deformation (permanent deformation).

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

[0116] The local tensile slope elements corresponding to the target abnormal slope change are determined from the tensile slope sequence. The time interval formed by the timestamps of all elements in the local tensile slope element is the time period in which the yield point of the nonwoven fabric is located. The element with the largest time in the time period is determined as the yield point, i.e., the boundary element. The tensile slope sequence is divided according to the boundary element to obtain the historical tensile state time period. This historical tensile state time period includes a rapid tensile period and a slow tensile period. The tensile slope sequence before the yield point is the rapid tensile period, and the tensile slope sequence after the yield point is the slow tensile period.

[0117] It should be noted that if a yield point exists before the current moment, then in the tensile slope sequence, the period before the yield point can be considered as the rapid stretching period, and the period after the yield point is the slow stretching period.

[0118] In this embodiment, both the rapid stretching period and the slow stretching period are considered as one historical stretching state period. Therefore, the number of historical stretching state period periods in the tension slope sequence can only be 1 or 2.

[0119] Based on the overall tensile deviation at the corresponding time point of the target element, the number of historical tensile state time periods, and the average overall tensile deviation for each historical tensile state time period, the true tensile degree at the target time is calculated. The calculation formula can be:

[0120]

[0121] in, This indicates the actual degree of stretching at the target time. This indicates the overall deviation of the tensile force of the target element at the corresponding time point. This indicates the number of time periods in the historical stretching state. Indicates the first The average deviation of the overall tensile force over a historical tensile period. This represents the natural exponential function.

[0122] The greater the actual stretching, the weaker the interference caused by improper clamping when the electronic tensile testing machine stretches the nonwoven fabric to the current moment. This reflects that the tensile data detected by the electronic tensile testing machine to the current moment is more realistic and reliable, and the highest value of the final generated tensile data is more in line with the actual needs.

[0123] Compared to traditional woven fabrics, nonwoven fabrics have randomly formed fibers, with some areas exhibiting denser fiber structures and others looser. These areas are randomly distributed within the nonwoven sample being tested, resulting in a noticeable uneven distribution of fibers on the surface. When an electronic tensile testing machine stretches the nonwoven sample vertically, the fabric as a whole experiences tensile force generated by the displacement of the clamps, causing different deformation changes in different local areas: the looser fiber structures (weaker tensile strength) deform first, followed by the denser fiber structures (stronger tensile strength). As the electronic tensile testing machine continuously drives the clamps, the distance between them increases, and the nonwoven fabric gradually reaches its tensile limit. Therefore, by combining the actual degree of stretching with the stretching distance, the tensile capacity of the randomly unevenly distributed fiber areas within the nonwoven fabric can be analyzed during the stretching process, allowing for real-time calculation of the degree of tearing during the stretching of the nonwoven fabric by the electronic tensile testing machine.

[0124] Taking the current state tension data sequence and state tension distance sequence as an example, the slope change sequence is segmented according to extreme points to obtain a monotonic slope change data segment. Since the slope change sequence is calculated from the state tension data sequence, each element in the monotonic slope change data segment corresponds to several elements in the state tension data sequence. Based on the correspondence between each element in the monotonic slope change data segment and the elements in the state tension data sequence, the state tension data sequence is segmented to obtain a monotonic tension data segment. Correspondingly, each element in the state tension data sequence also corresponds to an element in the state tension distance sequence; based on this correspondence, the state tension distance sequence is also segmented to obtain a tension distance data segment.

[0125] Taking any monotonic tensile force data segment and its corresponding tensile distance data segment as an example, obtain the mean tensile slope of the monotonic tensile force data segment and its corresponding tensile distance data segment. and the mean slope of distance and the mean change in the slope of the tension and the mean change in slope of distance Based on the actual stretching degree at the target time, the average tensile slope corresponding to the d-th monotonic tensile data segment, the average change in tensile slope corresponding to the d-th monotonic tensile data segment, the average distance slope corresponding to the d-th tensile distance data segment, and the average change in distance slope corresponding to the d-th tensile distance data segment, the difference in change between the d-th monotonic tensile data segment and the d-th tensile distance data segment is calculated. The calculation formula can be:

[0126]

[0127] in, This indicates the degree of variation. The greater the degree of variation, the weaker the synchronous change between the monotonic tensile data segment and the tensile distance data segment when their respective data change, reflecting the greater the degree of stretching resistance from the internal fibers of the nonwoven fabric at this time.

[0128] Due to the limitations of tensile testing machines, the most directly observable data are tensile force and tensile distance. However, in real-world scenarios, the localized over-density or under-density of nonwoven fabric fibers significantly impacts the relationship between tensile force and tensile distance. Therefore, to quantify these localized over-density and under-density issues, a three-dimensional coordinate system is constructed. The degree of change in tensile force and tensile distance are used as reference axes, and the difference in their variation is added as a new reference axis. This three-dimensional spatial distribution, constructed using these reference axes, allows for the quantification of localized over-density and under-density in the nonwoven fabric fibers.

[0129] A three-dimensional spatial coordinate system is constructed using the mean slope of the tension data segment as the x-axis, the mean slope of the distance data segment as the y-axis, and the variation difference as the z-axis. Furthermore, three-dimensional coordinate points for the d-th monotonic tension data segment and the d-th tension distance data segment are constructed using the mean slope of the tension data segment as the x-axis, the mean slope of the distance data segment as the y-axis, and the variation difference between the d-th and d-th monotonic tension data segments as the z-axis. These three-dimensional coordinate points are then represented in the spatial coordinate system, with each three-dimensional coordinate point corresponding to one monotonic tension data segment and one tension distance data segment.

[0130] The timestamp of each 3D coordinate point is taken as the timestamp of the element with the largest timestamp in the tensile distance data segment. Adjacent 3D coordinate points at each timestamp are connected to construct a vector, and the target vector is determined from this vector. The target vector is the vector whose timestamp is closest to the target time. The transition smoothness of the target vector is obtained, and the formula for calculating the transition smoothness of the target vector can be:

[0131]

[0132] in, Indicates smoothness of transition. This represents the difference in degrees between the angle between the target vector and the angle between adjacent vectors. This represents the difference in magnitude between the target vector and its neighboring vectors. The greater the smoothness of the transition, the weaker the fluctuation caused by the transition between adjacent monotonic tensile data segments, reflecting that the areas with weak fiber structure in the nonwoven fabric are closer to the tensile limit (therefore, during the stretching process, it is the areas with weak fiber structure that will inevitably break).

[0133] The angle between the target vector and the adjacent vectors represents the angle between the target vector and the adjacent vectors. The angle between the adjacent vectors represents the angle between the adjacent vector and the other adjacent vectors. The other adjacent vectors are the vectors that are adjacent to the adjacent vectors except for the target vector.

[0134] Based on the smoothness of the target vector transition and the difference in variation between each monotonic tension data segment and the corresponding tension distance data segment, the degree of fracture at the target moment is calculated using the following formula:

[0135]

[0136] in, Indicates the degree of breakage. Indicates the first The difference in variation between a monotonic tensile force data segment and its corresponding tensile distance data segment. This indicates the number of monotonic tension data segments existing at the target time. This represents the normalized function. The greater the degree of tearing, the more tension is required for the clamp to move when the nonwoven fabric is continuously stretched to the current moment. This reflects that the closer the time point of tearing occurs, the more the fibers inside the nonwoven fabric are stretched to their limit.

[0137] The data adjustment module 103 is used to adjust the termination conditions of the electronic tensile testing machine according to the degree of fracture at the target time.

[0138] For example, in this embodiment, the operation termination condition of the electronic tensile testing machine is adjusted. The operation termination condition of the electronic tensile testing machine is that the tensile force value at the target time decreases to a preset proportion of the maximum tensile force value. Stop operating the electronic tensile testing machine.

[0139] Therefore, the adjustment method can be as follows: when the degree of rupture at the target time is greater than the preset rupture degree threshold, obtain the duration between the target time and the first time within the slow stretching period. ,right After normalization, we get And calculate the adjusted weights. .

[0140] like If the tensile test time exceeds the preset threshold, it indicates that the tensile testing machine has stretched the fabric for a sufficiently long time before reaching its limit. This suggests that the nonwoven fabric sample tested has few or no weak fiber areas, and the decrease in tensile force when actual breakage occurs will be less significant. Therefore, a preset ratio for the maximum tensile force value is necessary. Adjust upwards, setting the maximum tensile force as a percentage. Adjusted to .

[0141] like If the tensile strength is less than or equal to the preset time threshold, it indicates that the tensile testing machine reaches its limit after a very short stretching time. This suggests that the nonwoven fabric sample tested has few or no areas of thin fiber thickness. The tensile strength will decrease more significantly when actual breakage occurs. Therefore, a preset ratio for the maximum tensile strength is necessary. Adjust the preset ratio of the maximum tensile force value. Adjusted to .

[0142] When the degree of fracture at the target time is less than or equal to the preset fracture degree threshold, the preset proportion of the maximum tensile force value is not applied. Adjustments will be made.

[0143] Optionally, the preset ratio of the maximum tensile force value in this embodiment The preset fracture severity threshold and preset duration threshold can be adjusted according to actual conditions, and no specific numerical limit is imposed here. In a preferred embodiment, the preset ratio of the maximum tensile force value is... The preset fracture severity threshold and preset duration threshold can be set to 50%, 0.75 and 0.5 respectively.

[0144] Furthermore, during the stretching process of each nonwoven fabric, a preset ratio of the maximum tensile force value is established. Adjust only once.

[0145] The present invention also proposes a special electronic tensile testing machine for nonwoven fabrics, including modules such as a tensile testing system for a special electronic tensile testing machine for nonwoven fabrics.

[0146] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0147] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tensile test system for nonwoven fabrics using an electronic tensile tester, characterized by, 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. The data analysis module determines the true degree of stretching at the target time based on the tensile slope sequence. Specifically, this includes: determining the slope change sequence and the average slope change sequence based on the tensile slope sequence; obtaining elements in the average slope change sequence that are less than a preset slope change threshold to obtain an abnormal slope change sequence; when the number of elements in the abnormal slope change sequence is equal to 0, determining that the nonwoven fabric is in a normal stretching state, and updating the state tensile data sequence and state tensile distance sequence 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, obtaining the overall tensile deviation at the time point corresponding to the target element in the tensile slope sequence, the number of historical stretching state time periods in the tensile slope sequence, and the average of the overall tensile deviation at each historical stretching state time period; and calculating the true degree of stretching at the target time based on the overall tensile deviation at the time point corresponding to the target element, the number of historical stretching state time periods, and the average of the overall tensile deviation at each historical stretching state time period. 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.

2. The electronic tensile testing system for nonwoven fabrics according to claim 1, wherein 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.

3. The electronic tensile testing system for nonwoven fabrics according to claim 1, wherein 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 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.

4. The electronic tensile testing system for nonwoven fabrics according to claim 1, wherein 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.

5. The electronic tensile testing system for nonwoven fabrics according to claim 1, wherein 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.

6. The electronic tensile testing system for nonwoven fabrics according to claim 1, wherein 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.

7. The electronic tensile testing system for nonwoven fabrics according to claim 1, wherein 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.

8. An electronic tensile tester for nonwoven fabrics, characterized by comprising: Including a tensile testing system for a nonwoven fabric-specific electronic tensile testing machine as described in any one of claims 1-7.

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