Method for testing high temperature tensile modulus of a fiber monofilament

Abstract

The application discloses a kind of testing methods of fiber monofilament high-temperature tensile elastic modulus, belong to the fiber tensile technical field.The existing method cannot completely real reaction fiber at high temperature real tensile property problem is solved.It includes: preparation fiber monofilament tensile sample;Fiber monofilament tensile sample is clamped to the clamping end of tensile testing machine testing device;The end of sample lining is cut on both sides of round hole;Close short type high-temperature furnace;Set target temperature and start heating, in the heating process, upper and lower clamping end is placed in room temperature;Start tensile testing machine and carry out tensile test, record stress-strain curve, obtain apparent tensile elastic modulus E (T1) ;According to the following formula, iterative calculation is carried out until the E (T1) n Of the n-th iteration is close to the E (T1) n‑1 Of the n-1-th iteration, then the final modified tensile elastic modulus E (T1) n Is obtained;The testing method of fiber monofilament high-temperature tensile elastic modulus of the application has high accuracy.

Description

Technical Field

[0001] This invention belongs to the field of fiber tensile property testing technology, specifically relating to a method for testing the high-temperature tensile elastic modulus of a fiber monofilament. Background Technology

[0002] Alumina fiber possesses high melting point, low density, high strength, and excellent high-temperature resistance. Its tensile modulus of elasticity under high-temperature conditions is one of its most important performance indicators. However, research has shown that the high-temperature tensile modulus of elasticity testing of alumina fiber monofilaments involves heat-treating the sample at high temperature, cooling it to room temperature, and then performing the tensile test at room temperature. This method cannot fully reflect the true tensile properties of the fiber under high-temperature conditions. Furthermore, no relevant standards, patents, or articles have been found regarding in-situ high-temperature tensile modulus of elasticity testing for fiber monofilaments.

[0003] The prior art provides a DMA method for high-temperature testing of fiber tensile modulus of elasticity. However, because DMA equipment is relatively precise and susceptible to contamination, and the operation is cumbersome, fiber debris and paper frame debris can easily contaminate the equipment during the high-temperature testing process. Therefore, the DMA method is not suitable for routine testing of fiber high-temperature tensile modulus of elasticity. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a method for testing the high-temperature tensile modulus of fiber monofilament, which can at least solve one of the following technical problems: (1) The existing DMA method is not suitable for testing the high-temperature tensile modulus of fiber in daily use; (2) The existing method uses heat treatment of the sample to be tested at high temperature and then cooling it to room temperature before conducting tensile tests at room temperature. This method cannot completely and truly reflect the actual tensile properties of the fiber under high-temperature conditions.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] On one hand, the present invention provides a method for testing the high-temperature tensile elastic modulus of a fiber monofilament, comprising the following steps:

[0007] S1. Adhere the fiber monofilament sample to the sample liner to obtain the fiber monofilament tensile sample.

[0008] S2. Clamp the prepared fiber monofilament tensile specimen onto the upper and lower clamping ends of the tensile testing machine; place the middle part of the fiber monofilament tensile specimen in a short high-temperature furnace.

[0009] S3. Cut off both sides of the end circular hole of the fiber monofilament tensile specimen and remove the cut-off paper pieces.

[0010] S4. Close the short-type high-temperature furnace and block the furnace opening with a baffle.

[0011] S5. After setting the target temperature, start heating. During the heating process, the upper and lower clamping ends should be placed at room temperature.

[0012] S6. When the heat preservation time is up, start the tensile testing machine to perform tensile testing, record the stress-strain curve, and obtain the apparent tensile elastic modulus E(T1).

[0013] S7. Perform iterative calculations according to the following formula (1) until the nth iteration yields E(T1). n E(T1) obtained from the (n-1)th iteration n-1 By approaching it infinitely, the final corrected tensile modulus of elasticity E(T1) is obtained. n ;

[0014]

[0015] In the formula: L0 is the length of the homogenization zone of the fiber monofilament sample in the high-temperature furnace; L1 is the length of the transition section outside the homogenization zone of the fiber monofilament sample; L is the length between the clamping ends of the fiber monofilament sample; T1 is the temperature of the homogenization zone in the short high-temperature furnace; T2 is the temperature of the clamping end of the fiber monofilament tensile sample; E(T1) is the apparent tensile modulus of elasticity of the fiber monofilament tensile sample measured at temperature T1; E(T2) is the tensile modulus of elasticity of the fiber monofilament tensile sample measured at temperature T2; n is the iteration number; E(T1) n-1 And E(T1) n These are the tensile moduli obtained after n-1 iterations and n iterations, respectively.

[0016] Furthermore, S1 includes the following steps:

[0017] Step 1: Use graph paper for the sample liner. Make a circular hole at each end of the sample liner along its length. The center line of the two circular holes should coincide with a certain line on the graph paper.

[0018] Step 2: Place the sample liner on a flat surface; apply quick-drying adhesive drop onto the center line of the outer edge of the two end holes on the sample liner;

[0019] Step 3: Place the fiber monofilament sample on the sample liner, with the center line of the fiber monofilament sample coinciding with the center line of the two end holes, and the two ends of the fiber monofilament sample passing through the quick-drying adhesive outside the two end holes.

[0020] Step 4: Cover the quick-drying adhesive and fiber monofilament sample on the sample liner along the outer edge of the two end holes, and stick the fiber monofilament sample on the sample liner to obtain the fiber monofilament tensile sample.

[0021] Furthermore, in step 1, multiple circular holes can be provided on the sample between the two end holes.

[0022] Furthermore, in step 1, the width of the sample liner is controlled to be 8–13 mm.

[0023] Furthermore, in step 1, the diameter of the end hole is controlled to be 5-7 mm.

[0024] Furthermore, in S2, the sample liner is clamped at the upper and lower clamping ends of the testing machine. The two sides of the sample liner should be parallel to the two sides of the clamping surface of the clamping end, and the sample liner should be in the lateral center position of the two clamping surfaces.

[0025] Furthermore, the short high-temperature furnace maintains a distance from both clamping ends.

[0026] Furthermore, the distance between the outer side of the short high-temperature furnace and the nearest clamping end is 65–75 mm.

[0027] Furthermore, an observation window is provided in the middle of the short-type high-temperature furnace.

[0028] Furthermore, an upper baffle is provided on the upper side of the short high-temperature furnace, and a lower baffle is provided on the lower side of the short high-temperature furnace.

[0029] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0030] (1) In the method for testing the high-temperature tensile elastic modulus of fiber monofilament of the present invention, the fiber monofilament tensile specimen is clamped by cold clamping and heated by a short high-temperature furnace. Before heating, the middle part of the specimen lining is cut off, and then the temperature rise and tensile test are performed to realize the test of the high-temperature in-situ apparent tensile elastic modulus of fiber monofilament. It is assumed that the temperature of the transition section of the fiber monofilament tensile specimen decreases linearly from the end of the uniform temperature section of the specimen to the transition section, and the tensile elastic modulus of the fiber monofilament changes linearly from high temperature to room temperature. Through formula derivation and iteration, the true tensile elastic modulus value is finally calculated.

[0031] (2) In the preparation process of the fiber monofilament tensile specimen of the present invention, the fiber monofilament specimen is glued to the specimen liner, and the specimen liner is punched with a punch to make round holes. This can effectively prevent the fiber monofilament from being too long and damaging the fiber. The fiber monofilament can be observed through several round holes in the middle of the specimen liner, thereby ensuring that the fiber is coaxial with the two round holes during the sample preparation process.

[0032] (3) The relative deviation between the high-temperature tensile elastic modulus of fiber monofilament measured by the test method of the present invention and the value measured by the DMA method is less than 0.15%, which is highly accurate.

[0033] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0034] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0035] Figure 1 This is a schematic diagram illustrating the preparation of a fiber monofilament tensile specimen.

[0036] Figure 2 This is a schematic diagram of the tensile testing machine's testing apparatus.

[0037] Figure 3 This is a schematic diagram of high-temperature stretching of a single fiber filament.

[0038] Figure label:

[0039] 1-Fiber monofilament sample, 2-Sample liner, 3-End round hole, 4-Quick-drying adhesive, 5-Paper sheet, 6-Upper clamping end, 7-Lower clamping end, 8-Short high-temperature furnace, 9-Upper baffle, 10-Lower baffle, 11-Observation window. Detailed Implementation

[0040] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and are used to illustrate the principles of the present invention.

[0041] This invention provides a method for testing the high-temperature tensile elastic modulus of a fiber monofilament, comprising the following steps:

[0042] S1. Adhere the fiber monofilament sample 1 to the sample liner 2 to obtain the fiber monofilament tensile sample.

[0043] S2. Clamp the prepared fiber monofilament tensile specimen onto the upper and lower clamping ends of the tensile testing machine; place the middle part of the fiber monofilament tensile specimen in a short high-temperature furnace.

[0044] S3. Cut off both sides of the end circular hole of the specimen liner 2 of the fiber monofilament tensile specimen and remove the cut-off paper pieces.

[0045] S4. Close the short-type high-temperature furnace and block the furnace opening with a baffle.

[0046] S5. After setting the target temperature, start heating. During the heating process, the upper and lower clamping ends should be placed at room temperature.

[0047] S6. When the heat preservation time is up, start the tensile testing machine to perform tensile testing, record the stress-strain curve, and obtain the apparent tensile elastic modulus E(T1).

[0048] S7. Perform iterative calculations according to the following formula (1) until the nth iteration yields E(T1). nE(T1) obtained from the (n-1)th iteration n-1 If the value is infinitely close (relative deviation less than 0.5%), then the final corrected tensile modulus E(T1) is obtained. n ;

[0049]

[0050] In the formula, L0 is the length of the homogenization zone of the fiber monofilament sample in the high-temperature furnace, L1 is the length of the transition section from the homogenization zone of the fiber monofilament sample to the clamping end, and L is the length between the two clamping ends of the fiber monofilament sample; T1 is the temperature of the homogenization zone in the short high-temperature furnace, T2 is the temperature of the clamping end of the fiber monofilament tensile sample (i.e., room temperature), E(T1) is the apparent tensile modulus of elasticity of the fiber monofilament tensile sample measured at temperature T1, and E(T2) is the tensile modulus of elasticity of the fiber monofilament tensile sample measured at temperature T2; n is the iteration number. When n = 1, E(T1) n-1 E(T1)0 represents the apparent elastic modulus E(T1) measured at temperature T1. n-1 And E(T1) n These are the tensile moduli obtained after n-1 iterations and n iterations, respectively.

[0051] Specifically, the fiber monofilament can be alumina fiber monofilament.

[0052] Specifically, S1 includes the following steps:

[0053] Step 1, as follows Figure 1 As shown, the sample liner 2 is made of coordinate paper. A circular hole 3 is punched at each end of the sample liner 2 along its length. The center line of the two circular holes 3 coincides with a certain gradation line in the coordinate paper.

[0054] Step 2: Place the sample liner 2 on a flat surface; drip the quick-drying adhesive 4 onto the center line of the outer edge of the two end holes 3 on the sample liner 2;

[0055] Step 3: Place the fiber monofilament sample 1 on the sample liner 2, with the center line of the fiber monofilament sample 1 coinciding with the center line of the two end holes 3, and the two ends of the fiber monofilament sample 1 passing through the quick-drying adhesive 4 outside the two end holes 3.

[0056] Step 4: Cover the quick-drying adhesive 4 and the fiber monofilament sample 1 on the sample liner 2 along the outer edge of the two end holes 3. Adhere the fiber monofilament sample 1 to the sample liner 2 to obtain the fiber monofilament tensile sample.

[0057] Specifically, in step 1 above, multiple round holes can be provided on the sample liner 2 between the two end round holes 3. Since the fiber monofilament sample 1 is usually transparent, the presence of round holes can serve as a comparison, allowing the fiber monofilament sample to be seen more clearly during sample preparation. Furthermore, the round holes on the sample liner facilitate cutting the sample liner during testing.

[0058] Specifically, in step 1 above, considering that the width of the sample liner 2 is too large, the centering is difficult to control during clamping, and the matching with the clamping surface of the clamping end of the tensile testing machine is poor, the width of the sample liner 2 is controlled to be 8-13 mm.

[0059] Specifically, in step 1 above, the diameter of the control end circular hole 3 is 5-7 mm.

[0060] Specifically, in step 1 above, a hole punch can be used to make a round hole.

[0061] Specifically, in step 1 above, the sample preparation method of the fiber monofilament tensile specimen of the present invention uses coordinate paper as a sample backing and pastes the fiber monofilament specimen along the engraving lines of the coordinate paper. This can keep the fiber monofilament specimen vertical, thereby ensuring the centering of the fiber monofilament specimen during the test and improving the accuracy of the test results.

[0062] Specifically, in step 2 above, quick-drying adhesive is applied to the outside of the two round holes of the sample liner, and then the fiber monofilament sample is placed at the center line of the two round holes. The adhesive area is then covered with a piece of paper of appropriate size. At this time, the prepared fiber monofilament sample has good centering and the adhesive area is flat. During the clamping test, the accuracy of the test results will not be affected by the presence of hard adhesive dots.

[0063] Specifically, in S2 above, such as Figure 2 The diagram shows the structure of the tensile testing machine. The prepared fiber monofilament tensile specimen is clamped at the upper clamping end 6 and the lower clamping end 7 of the tensile testing machine. A part of the fiber monofilament tensile specimen is placed in the short high-temperature furnace 8. The short high-temperature furnace 8 has an upper baffle 9 on its upper side and a lower baffle 10 on its lower side. An observation window 11 is provided in the middle of the short high-temperature furnace 8.

[0064] Specifically, in S7 above, the schematic diagram of high-temperature stretching of the fiber monofilament is as follows: Figure 3 As shown. L0 is the length of the homogenization zone of the fiber monofilament sample in the high-temperature furnace, and L1 is the length of the transition section from the homogenization zone of the fiber monofilament sample to the clamping end of the fixture.

[0065] Specifically, in S2 above, the sample liner is clamped at the upper and lower clamping ends of the testing machine. The two sides of the sample liner should be parallel to the two sides of the clamping surface of the clamping end. The sample liner is located in the transverse center position of the two clamping surfaces, so that the fiber monofilament tensile sample can better maintain the centering during the test.

[0066] Specifically, in S2 above, the short high-temperature furnace 8 should be kept at a certain distance from the two clamping ends to protect the clamping ends from damage by high-temperature radiation.

[0067] Specifically, in S2 above, the distance between the outer side of the short high-temperature furnace 8 and the nearest clamping end is 65-75mm, for example 66mm, 67mm, 68mm, 69mm, 70mm, 71mm, 72mm, 73mm, or 74mm.

[0068] It should be noted that the test method of this invention uses a cold-clamping method and a short-type high-temperature furnace for in-situ tensile testing. Because the high-temperature test sample is placed in the middle of the high-temperature furnace and outside the high-temperature heating device at both ends, the obtained high-temperature tensile modulus of elasticity is not accurate. Therefore, the inventors have corrected the tensile modulus of elasticity data. The calculation method for the corrected tensile modulus of elasticity in S7 above was derived by the inventors through long-term in-depth research: The inventors tested a series of alumina fiber monofilaments that underwent high-temperature treatment at different temperatures and then tensile tests at room temperature. Extensive experiments verified that the tensile modulus of elasticity of the alumina fiber monofilament increases with increasing temperature. Through in-depth research, the inventors hypothesized that during the high-temperature in-situ tensile testing of alumina fiber monofilaments using the cold-clamping method, the tensile modulus of elasticity E changes linearly from high temperature to room temperature, i.e.: E(T)=a0+a1T

[0069] Then we have:

[0070] We obtain a0 and a1.

[0071] Assume that the temperature of the fiber monofilament changes linearly within the transition section, i.e.: T = b0 + b1x

[0072] Then we have:

[0073] We obtain b0 and b1.

[0074] Solve for the total elongation ΔL during the stretching of a single fiber filament.

[0075] Elongation within the uniform temperature range L0:

[0076] Consider a small element dx at point x within the transition section of the fiber monofilament, where the temperature is T(x). Its deformation under the tensile stress σ is δ(dx).

[0077] Then we have: T(x) = b0 + b1x

[0078] E(x,T)=a0+a1T=a0+a1b0+a1b1x

[0079] And from

[0080]

[0081] have to

[0082]

[0083]

[0084] Therefore, the total deformation of the fiber is

[0085] ΔL=ΔL0+2ΔL1

[0086] Substituting into (6) and (7) derived above.

[0087]

[0088] Therefore, the tensile modulus of elasticity after one iteration is:

[0089]

[0090]

[0091] The tensile modulus of elasticity after two iterations is:

[0092]

[0093] ...

[0094] The tensile modulus of elasticity after n iterations is:

[0095]

[0096] When E(T1) n With E(T1) n-1 If the value is infinitely close (relative deviation less than 0.5%), then the final corrected tensile modulus E(T1) is obtained. n .

[0097] Compared with the prior art, the method for testing the high-temperature tensile modulus of fiber monofilaments in this invention uses a cold clamping method to hold the fiber monofilament tensile specimen, heats it with a short high-temperature furnace, cuts off the middle part of the specimen liner before heating, and then performs heating and tensile testing to achieve the in-situ high-temperature apparent tensile modulus of fiber monofilaments testing. Assuming that the temperature of the transition section of the fiber monofilament tensile specimen decreases linearly from the end of the specimen with uniform temperature to the transition section, the tensile modulus of fiber monofilaments changes linearly from high temperature to room temperature. Through formula derivation and iteration, the true tensile modulus value is finally calculated.

[0098] In the preparation process of the fiber monofilament tensile specimen of the present invention, the fiber monofilament specimen is adhered to the specimen liner, and the specimen liner is punched with a punch to make round holes. This can effectively prevent the fiber monofilament from being too long and being damaged. Moreover, the fiber monofilament can be observed through several round holes in the middle of the specimen liner, thereby ensuring that the fiber is coaxial with the two round holes during the sample preparation process.

[0099] The method for testing the high-temperature tensile modulus of fiber monofilaments of the present invention yields a value with a relative deviation of less than 0.15% from the value obtained by the DMA method, demonstrating high accuracy.

[0100] Example 1

[0101] like Figure 1-3 As shown, this embodiment provides a method for testing the high-temperature tensile elastic modulus of a fiber monofilament, including the following steps:

[0102] S1. Adhere the fiber monofilament sample 1 to the sample liner 2 to obtain the fiber monofilament tensile sample.

[0103] S2. Clamp the prepared fiber monofilament tensile specimen onto the upper and lower clamping ends of the tensile testing machine; place a portion of the fiber monofilament tensile specimen in a short high-temperature furnace.

[0104] S3. Cut off both sides of the end circular hole of the specimen liner 2 of the fiber monofilament tensile specimen and remove the cut-off paper pieces.

[0105] S4. Close the short-type high-temperature furnace and block the furnace opening with a baffle.

[0106] S5. After setting the target temperature T1, start heating. During the heating process, the upper and lower clamping ends are placed at room temperature.

[0107] S6. When the heat preservation time is up, start the tensile testing machine to perform tensile testing, record the stress-strain curve, and obtain the apparent tensile elastic modulus E(T1).

[0108] S7. Measure the tensile modulus E(T2) of a fiber monofilament tensile specimen at room temperature T2.

[0109] S8. Perform iterative calculations according to the following formula (1) until the nth iteration yields E(T1). n E(T1) obtained from the (n-1)th iteration n-1 If the value is infinitely close (relative deviation less than 0.5%), then the final corrected tensile modulus E(T1) is obtained. n ;

[0110]

[0111] In this embodiment:

[0112] T1 is the temperature of the uniform temperature zone inside the furnace, which is 600℃;

[0113] T2 is the temperature at the fiber clamping end, which is 23℃; E(T1) is the apparent tensile modulus of elasticity measured at temperature T1, which is 231GPa; E(T2) is the tensile modulus of elasticity of the fiber measured at T2, which is 228GPa; L0 is the length of the uniform temperature zone of the fiber monofilament sample in the high-temperature furnace, which is 20mm; L1 is the length of the transition section from the uniform temperature zone of the fiber monofilament sample to the clamping end of the fixture, which is 115mm; L is the length between the two clamping ends of the fiber monofilament sample, which is 250mm.

[0114] The result of one iteration is E(T1)1 = 229.66 GPa;

[0115] The second iteration yielded E(T1)2 = 229.55 GPa;

[0116] The result obtained after three iterations is E(T1)3 = 229.54 GPa;

[0117] Since the data obtained in the third iteration is infinitely close to that obtained in the second iteration (relative deviation less than 0.5%), the final corrected tensile modulus E(T1) is obtained. n The value is E(T1)3 = 229.54 GPa.

[0118] Specifically, the fiber monofilament is an alumina fiber monofilament.

[0119] Specifically, S1 includes the following steps:

[0120] Step 1, as follows Figure 1 As shown, the sample liner 2 is made of coordinate paper. A circular hole 3 is punched at each end of the sample liner 2 along its length. The center line of the two circular holes 3 coincides with a certain gradation line in the coordinate paper.

[0121] Step 2: Place the sample liner 2 on a flat surface; drip the quick-drying adhesive 4 onto the center line of the outer edge of the two end holes 3 on the sample liner 2;

[0122] Step 3: Place the fiber monofilament sample 1 on the sample liner 2, with the center line of the fiber monofilament sample 1 coinciding with the center line of the two end holes 3, and the two ends of the fiber monofilament sample 1 passing through the quick-drying adhesive 4 outside the two end holes 3.

[0123] Step 4: Cover the quick-drying adhesive 4 and the fiber monofilament sample 1 on the sample liner 2 along the outer edge of the two end holes 3. Adhere the fiber monofilament sample 1 to the sample liner 2 to obtain the fiber monofilament tensile sample.

[0124] Specifically, in step 1 above, multiple round holes can also be provided on the sample liner 2 between the two end round holes 3.

[0125] Specifically, in step 1 above, the width of the sample liner 2 is controlled to be 10 mm.

[0126] Specifically, in step 1 above, the diameter of the control end circular hole 3 is 6mm.

[0127] The distance between the outer side of the short high-temperature furnace 8 and the nearest clamping end is 70mm.

[0128] The final corrected tensile modulus E(T1) at temperature T1 measured in this embodiment. n The value is 229.54 GPa.

[0129] The inventors used the DMA method to measure the high-temperature tensile elastic modulus of the fiber monofilament at temperature T1 as 230.12 GPa.

[0130] It can be seen that the relative deviation between the high-temperature tensile elastic modulus of the fiber monofilament measured by the method of the present invention and the value measured by the DMA method is 0.13%, which shows high accuracy.

[0131] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for testing the high-temperature tensile elastic modulus of a fiber monofilament, characterized in that, Includes the following steps: S1. Adhere the fiber monofilament sample (1) to the sample liner (2) to obtain the fiber monofilament tensile sample. S2. The prepared fiber monofilament tensile specimen is clamped to the upper and lower clamping ends of the tensile testing machine; the middle part of the fiber monofilament tensile specimen is placed in the short high-temperature furnace (8). S3. Cut off both sides of the end round hole of the fiber monofilament tensile specimen (2) and remove the cut paper pieces. S4. Close the short high-temperature furnace (8) and cover the furnace opening with a baffle. S5. After setting the target temperature, start heating. During the heating process, the upper and lower clamping ends should be placed at room temperature. S6. After the heat preservation time is up, start the tensile testing machine to perform a tensile test, record the stress-strain curve, and obtain the apparent tensile modulus of elasticity. ; S7. Perform iterative calculations according to the following formula (1) until the nth iteration is obtained. The result obtained from the (n-1)th iteration By getting infinitely close, the final corrected tensile modulus of elasticity is obtained. ; (1) In the formula: L0 is the length of the homogenization zone of the fiber monofilament sample in the high-temperature furnace; L1 is the length of the transition section outside the homogenization zone of the fiber monofilament sample; L is the length between the clamping ends of the fiber monofilament sample; T1 is the temperature of the homogenization zone in the short high-temperature furnace; T2 is the temperature of the clamping end of the fiber monofilament tensile sample; E(T1) is the apparent tensile modulus of elasticity of the fiber monofilament tensile sample measured at temperature T1; E(T2) is the tensile modulus of elasticity of the fiber monofilament tensile sample measured at temperature T2; n is the number of iterations. and These are the tensile moduli obtained after n-1 iterations and n iterations, respectively.

2. The method for testing the high-temperature tensile elastic modulus of a fiber monofilament according to claim 1, characterized in that, S1 includes the following steps: Step 1: The sample liner (2) is made of coordinate paper. A circular hole (3) is made at each end of the sample liner (2) along its length. The center line of the two circular holes (3) coincides with a certain line on the coordinate paper. Step 2: Place the sample liner (2) on a flat surface; drip the quick-drying adhesive (4) onto the center line of the outer edge of the two end holes (3) on the sample liner (2); Step 3: Place the fiber monofilament sample (1) on the sample liner (2). The fiber monofilament sample (1) coincides with the center line of the two end holes (3). The two ends of the fiber monofilament sample (1) pass through the quick-drying adhesive (4) outside the two end holes (3). Step 4: Place the paper sheet (5) along the outer edge of the two end holes (3) onto the quick-drying adhesive (4) on the sample liner (2) and the fiber monofilament sample (1), and stick the fiber monofilament sample (1) onto the sample liner (2) to obtain the fiber monofilament tensile sample.

3. The method for testing the high-temperature tensile elastic modulus of a fiber monofilament according to claim 2, characterized in that, In step 1, multiple circular holes are also provided on the sample between the two end circular holes.

4. The method for testing the high-temperature tensile elastic modulus of a fiber monofilament according to claim 2, characterized in that, In step 1, the width of the sample liner (2) is controlled to be 8~13mm.

5. The method for testing the high-temperature tensile elastic modulus of a fiber monofilament according to claim 2, characterized in that, In step 1, the diameter of the control end hole (3) is 5~7mm.

6. The method for testing the high-temperature tensile elastic modulus of a fiber monofilament according to claim 1, characterized in that, In S2, the sample liner is clamped at the upper and lower clamping ends of the testing machine. The two sides of the sample liner are parallel to the two sides of the clamping surface of the clamping end, and the sample liner is located in the lateral center position of the two clamping surfaces.

7. The method for testing the high-temperature tensile elastic modulus of a fiber monofilament according to claim 1, characterized in that, The short high-temperature furnace (8) is kept at a distance from both clamping ends.

8. The method for testing the high-temperature tensile elastic modulus of a fiber monofilament according to claim 7, characterized in that, The distance between the outer side of the short high-temperature furnace (8) and the nearest clamping end is 65~75mm.

9. The method for testing the high-temperature tensile modulus of elasticity of a fiber monofilament according to any one of claims 1 to 8, characterized in that, The short-type high-temperature furnace (8) is provided with an observation window (11) in the middle.

10. The method for testing the high-temperature tensile modulus of elasticity of a fiber monofilament according to any one of claims 1 to 8, characterized in that, The upper side of the short high-temperature furnace (8) is provided with an upper baffle (9), and the lower side of the short high-temperature furnace (8) is provided with a lower baffle (10).

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