CN111122343A - Prediction method for service life of plastic sleeve - Google Patents
Prediction method for service life of plastic sleeve Download PDFInfo
- Publication number
- CN111122343A CN111122343A CN201911394802.4A CN201911394802A CN111122343A CN 111122343 A CN111122343 A CN 111122343A CN 201911394802 A CN201911394802 A CN 201911394802A CN 111122343 A CN111122343 A CN 111122343A
- Authority
- CN
- China
- Prior art keywords
- temperature
- time
- aging
- test
- selecting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/18—Performing tests at high or low temperatures
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/20—Investigating strength properties of solid materials by application of mechanical stress by applying steady bending forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/30—Investigating strength properties of solid materials by application of mechanical stress by applying a single impulsive force, e.g. by falling weight
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/40—Investigating hardness or rebound hardness
- G01N3/42—Investigating hardness or rebound hardness by performing impressions under a steady load by indentors, e.g. sphere, pyramid
- G01N3/44—Investigating hardness or rebound hardness by performing impressions under a steady load by indentors, e.g. sphere, pyramid the indentors being put under a minor load and a subsequent major load, i.e. Rockwell system
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/0003—Steady
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/001—Impulsive
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0017—Tensile
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0023—Bending
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0076—Hardness, compressibility or resistance to crushing
- G01N2203/0078—Hardness, compressibility or resistance to crushing using indentation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/0202—Control of the test
- G01N2203/0212—Theories, calculations
- G01N2203/0218—Calculations based on experimental data
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/022—Environment of the test
- G01N2203/0222—Temperature
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/026—Specifications of the specimen
- G01N2203/0262—Shape of the specimen
- G01N2203/0274—Tubular or ring-shaped specimens
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Abstract
The invention provides a method for predicting the service life of a plastic sleeve, and belongs to the technical field of plastic sleeves. The technical problem that the service life of an existing plastic sleeve is not convenient enough is solved. The prediction method comprises the following steps: a. sampling: selecting a plurality of groups of sample strips of the plastic sleeve material, and measuring the initial value of the hardness (Rockwell) or tensile strength or bending strength or unnotched impact strength of the sample strips; b. and (3) aging determination: selecting at least 3 different temperatures T (K) within the range of 70-200 ℃, grouping the splines, respectively putting the splines into aging rooms with at least 3 selected different temperatures for aging tests, and recording the time point t (h) when the change rate of each performance index value of the test item reaches 50%, wherein the time point t (h) is critical time; c. and (3) analysis and calculation: the shelf life of the plastic sleeve at normal temperature is calculated by using an Arrhenius equation and an extrapolation method. The prediction method adopted by the invention is accurate and reliable, and takes less time.
Description
Technical Field
The invention belongs to the technical field of plastic sleeves, and relates to a method for predicting the service life of a plastic sleeve.
Background
The plastic sleeve is widely used, and gradually deteriorates in long-term storage, and finally loses use value; the service life of the intelligent monitoring system is accurately predicted by a scientific method, so that the intelligent monitoring system has important practical significance for safe and reliable use; the storage period is determined by using an actual storage method, and the method has the advantages of simplicity, practicability and reliable data, but the requirement for screening a formula and identifying the material performance is far from being met after a long time.
Chinese patent (publication number: CN106323848B, granted publication date: 2018-11-02) discloses a method for predicting the expected service life of a composite anticorrosive coating of a metal pipeline, which comprises the following steps:
selecting soil in a typical area as an experimental site for burying a metal pipeline, and excavating a test pit for burying a sample in the selected soil in the typical area;
secondly, preparing a metal pipeline to be tested into samples and embedding the samples in the test pits, wherein the number of the same sample embedded parallel samples in the soil of the same typical area is 6;
digging out the samples according to the preset digging years of 1 year, 2 years, 4 years and 6 years, and removing soil on the surfaces of the samples;
(IV) drying the sample, and then calculating the proportion S1 of the red corrosion area on the surface of the sample to the total surface area of the sample and the proportion S2 of the area of the organic coating on the surface of the sample, which is peeled off and exposed to the lower zinc layer, to the total surface area of the sample;
removing corrosion products on the surface of the sample, observing whether the surface of the metal substrate of the sample has a corrosion pit or not, if so, measuring the depth of the corrosion pit, and when the depth of the corrosion pit is less than 0.3mm, carrying out the following steps;
and (VI) taking the corrosion age as an abscissa and the equivalent corrosion area of the composite coating as S, then S is S1+0.5S2, taking S as an ordinate, calculating a unitary quadratic equation Y which is aX + bX + c and fits the corrosion area of the coating, determining coefficients of all terms of the equation, predicting the age of the composite anticorrosive coating when the equivalent corrosion area of the coating reaches 100% by using the equation, and assuming that A is used here, and determining the expected service life age of the tested sample composite anticorrosive coating as A.
The prediction method in the patent literature is mainly applied to the expected service life of the composite anticorrosive coating of the metal pipeline and cannot be suitable for the plastic sleeve; moreover, the method requires six years of time, takes too long time, is not wide enough and convenient to use, and in addition, the accuracy of the prediction method is not high enough.
Disclosure of Invention
The invention provides a method for predicting the service life of a plastic sleeve aiming at the problems in the prior art, and the technical problems to be solved by the invention are as follows: how to provide an accurate, reliable and short-time prediction method for the service life of a plastic casing.
The purpose of the invention can be realized by the following technical scheme:
a prediction method for the service life of a plastic sleeve is characterized by comprising the following steps:
a. sampling: selecting a plurality of groups of sample strips of the plastic sleeve material, and measuring the initial value of the hardness (Rockwell) or tensile strength or bending strength or unnotched impact strength of the sample strips;
b. and (3) aging determination: selecting at least 3 different temperatures T (K) within the interval range of 70-200 ℃, grouping the sample strips, respectively putting the sample strips into aging rooms with at least 3 different temperatures for aging test, selecting at least 5 time nodes under each temperature condition, measuring the numerical values of the sample strips corresponding to the step a for multiple times according to the method in the step a, and recording the time point t (h) when the change rate of each performance index value of the test item point reaches 50%, wherein the time point t (h) is critical time;
c. and (3) analysis and calculation: forming a relation graph between the logarithm log T of the critical value time and the reciprocal 1/T of the absolute temperature of the testing temperature and a linear equation by using an Arrhenius equation; and calculating the storage life of the plastic sleeve at normal temperature by using an extrapolation method according to the linear equation.
The principle is as follows: the aging test temperature in the technical scheme selects the test temperature suitable for evaluating the performance of the plastic sleeve material, the aging test is carried out at least 3 temperatures, the service life is obtained by an extrapolation method with required accuracy, the time required for reaching the critical value is at least 1000h at the selected lowest temperature, and the time for reaching the critical value is not less than 100h at the same selected highest temperature. In the technical scheme, the storage period of the plastic casing material indoors is quickly estimated according to the change of physical and mechanical properties and the like of the plastic casing material by using a hot air aging test; the change of the selected performance of the plastic casing and the time for reaching the specified critical value are measured through hot air aging, the service life of the plastic casing is calculated by utilizing an Arrhenius equation diagram, scientific and reliable theoretical basis and accurate prediction result are provided, and the consumed time is short.
In the method for predicting the service life of the plastic casing, in the step a and the step b, if the hardness (Rockwell) value is measured, 5I-type sample bars are taken, 5 points are measured for each sample bar, and the recorded data are averaged; if the tensile strength value is measured, 5I-shaped sample strips with finished hardness are taken for testing, data are recorded, and an average value is taken; if the bending strength value is measured, 5 bending sample strips are taken for testing, and the test result is averaged and recorded; and if the unnotched impact strength value is measured, taking 5 unnotched impact sample bars for testing, recording test results and taking an average value. The hardness (Rockwell) value is measured according to the GB/T3398.2 standard, the tensile strength test is carried out according to the GB/T1447 standard when the tensile strength value is measured, the bending strength value is measured according to the GB/9341 standard, and the unnotched impact strength value is measured according to the GB/T1043 standard. Various data measured by the method are more accurate and reliable.
In the above method for predicting the service life of the plastic casing, in the step b, the following 4 different aging temperatures are selected:
①, selecting a temperature of 110 ℃ (an absolute temperature of 383.15K), and respectively selecting 6 time nodes of 0h, 1560h (65d), 2016h (84d), 2496h (104d), 2592h (108d) and 2712h (113d) at the temperature for measurement;
②, selecting a temperature of 125 ℃ (absolute temperature 398.15K), and selecting 6 time nodes of 0h, 1008h (42d), 1560h (65d), 1632h (68d), 1704h (71d) and 1776h (74d) respectively at the temperature for measurement;
③, selecting the temperature of 150 ℃ (absolute temperature 423.15K), and respectively selecting 6 time nodes of 0h, 96h (4d), 168h (7d), 240h (10d), 312h (13d) and 360h (15d) at the temperature for measurement;
④, selecting the temperature of 90 ℃ (363.15K absolute), and selecting 6 time nodes of 0h, 1008h (42d), 3000h (125d), 5016h (209d), 5088h (212d) and 5160h (215d) respectively at the temperature for measurement.
In the method for predicting the service life of the plastic casing, in the step b, 2 groups of data are made for each test, and the time t (h) when the change rate of the average value of the performance indexes of the test item reaches 50% is recorded, wherein the longest time t (h) is not less than 1000h, and the shortest time t (h) is not less than 100 h. Furthermore, when the change rate of a certain performance index is close to 50%, the observation period should be encrypted, so as to ensure the accurate reliability of the time t (h).
In the method for predicting the service life of the plastic casing, in the step a, 5 plastic casing sample strips without notch impact are taken for testing, the initial value of the notch-free impact strength is tested, the test result is recorded, and the average value is taken; in the step b, according to the test result that 3 corresponding unnotched impact strengths at the aging test temperatures (110 ℃, 125 ℃ and 150 ℃) are changed along with time, a corresponding graph of unnotched impact strength performance retention percentage-aging time h is made, and the relationship of unnotched impact strength performance retention percentage y (%) -aging time x (h) is as follows: when the aging test temperature is 110 ℃, y is 2E-05x2-0.0954x + 99.628; when the aging test temperature is 125 ℃, y is 5E-05x2-0.1508x + 99.676; when the aging test temperature is 150 ℃, y is 0.0017x2-0.8432x + 89.881; the logarithm of the critical time y '(logt) -the reciprocal of the absolute temperature of the test temperature x' (1/T) is thus derived as: y 'is 4.3218 x' -8.4578; the formula is used for obtaining the critical time at normal temperature, namely the service life of the plastic sleeve.
In the technical scheme, because the sample still keeps certain unnotched impact strength and is not lower than the index value when the sample fails at high temperature, the critical value of the unnotched impact strength which is reduced to 50 percent of the original measured value is selected as the judgment standard of the service life limit of the plastic sleeve.
In the method for predicting the service life of the plastic casing, in the step a, 5I-shaped sample strips with finished hardness are taken for testing, a tensile strength test is carried out, data are recorded, and an average value is taken to obtain an initial value of the tensile strength; in the step b, according to the test result that 3 aging test temperatures (110 ℃, 125 ℃ and 150 ℃) correspond to the change of the tensile strength along with the time, a corresponding graph of the tensile strength performance retention rate to the aging time h is made, and the relational expression of the tensile strength performance retention rate y (%) -the aging time x (h) is as follows: when the aging test temperature is 110 ℃, y is 2E-05x2-0.0954x + 99.622; when the aging test temperature is 125 ℃, y is 5E-05x2-0.151x + 99.679; when the aging test temperature is 150 ℃, y is 0.0017x2-0.8411x + 89.869; the logarithm of the critical time y '(logt) -the reciprocal of the absolute temperature of the test temperature x' (1/T) is thus derived as: y '4.3695 x' -8.5436; the formula is used for obtaining the critical time at normal temperature, namely the service life of the plastic sleeve.
In the method for predicting the service life of the plastic sleeve, as a third scheme, the service life of the plastic sleeve can be obtained by recording the final failure force value through a pulling resistance test. And (3) selecting the three different temperature values for carrying out an aging test, taking 5D 2 embedded sleeves for carrying out a limit anti-pulling test according to the TB/T3395 standard in each test, and recording the final damage force value. The time when the variation rate of the mean value of the ultimate pullout resistance of the D2 embedded casing reaches 50% or 110KN is recorded. The service life of the plastic sleeve is calculated according to the determination of the time-temperature limit after long-term thermal exposure of the GB/T7142-2002 plastic.
Compared with the prior art, the change of the selective performance of the plastic casing and the time for reaching the specified critical value are measured through hot air aging, the service life of the plastic casing is calculated by utilizing the Arrhenius equation diagram, scientific and reliable theoretical basis and accurate prediction result are provided, and the consumed time is short.
Drawings
FIG. 1 is a graph corresponding to the unnotched impact strength property retention y (%) - -aging time x (h) in example one.
FIG. 2 is a graph of log of threshold time logt versus inverse 1/T of absolute temperature of test temperature for one example.
FIG. 3 is a graph corresponding to the tensile strength property retention y (%) - -aging time x (h) in example two.
FIG. 4 is a graph of log of threshold time logt versus reciprocal 1/T of absolute temperature of test temperature for example two.
Detailed Description
The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.
Example one
The embodiment provides a method for predicting the service life of a plastic sleeve, which is characterized by comprising the following steps of:
a. sampling: selecting a plurality of groups of sample strips of the plastic sleeve material, and measuring the initial value of the hardness (Rockwell) or tensile strength or bending strength or unnotched impact strength of the sample strips;
b. and (3) aging determination: selecting at least 3 different temperatures T (K) within the interval range of 70-200 ℃, grouping the sample strips, respectively putting the sample strips into aging rooms with at least 3 different temperatures for aging test, selecting at least 5 time nodes under each temperature condition, measuring the numerical values of the sample strips corresponding to the step a for multiple times according to the method in the step a, and recording the time point t (h) when the change rate of each performance index value of the test item point reaches 50%, wherein the time point t (h) is critical time;
c. and (3) analysis and calculation: forming a relation graph between the logarithm log T of the critical value time and the reciprocal 1/T of the absolute temperature of the testing temperature and a linear equation by using an Arrhenius equation; and calculating the storage life of the plastic sleeve at normal temperature by using an extrapolation method according to the linear equation.
Further, in the step a and the step b, if the hardness (Rockwell) value is measured, 5I-type sample strips are taken, 5 points are measured for each sample, and the recorded data is averaged; if the tensile strength value is measured, 5I-shaped sample strips with finished hardness are taken for testing, data are recorded, and an average value is taken; if the bending strength value is measured, 5 bending sample strips are taken for testing, and the test result is averaged and recorded; and if the unnotched impact strength value is measured, taking 5 unnotched impact sample bars for testing, recording test results and taking an average value. The hardness (Rockwell) value is measured according to the GB/T3398.2 standard, the tensile strength test is carried out according to the GB/T1447 standard when the tensile strength value is measured, the bending strength value is measured according to the GB/9341 standard, and the unnotched impact strength value is measured according to the GB/T1043 standard. Various data measured by the method are more accurate and reliable.
In step b, the following 4 different aging temperatures are selected:
①, selecting a temperature of 110 ℃ (an absolute temperature of 383.15K), and respectively selecting 6 time nodes of 0h, 1560h (65d), 2016h (84d), 2496h (104d), 2592h (108d) and 2712h (113d) at the temperature for measurement;
②, selecting a temperature of 125 ℃ (absolute temperature 398.15K), and selecting 6 time nodes of 0h, 1008h (42d), 1560h (65d), 1632h (68d), 1704h (71d) and 1776h (74d) respectively at the temperature for measurement;
③, selecting the temperature of 150 ℃ (absolute temperature 423.15K), and respectively selecting 6 time nodes of 0h, 96h (4d), 168h (7d), 240h (10d), 312h (13d) and 360h (15d) at the temperature for measurement;
④, selecting the temperature of 90 ℃ (363.15K absolute), and selecting 6 time nodes of 0h, 1008h (42d), 3000h (125d), 5016h (209d), 5088h (212d) and 5160h (215d) respectively at the temperature for measurement.
And 2 groups of data are made in each test, the time t (h) when the change rate of the average value of each performance index of the test item points reaches 50%, the longest time t (h) is more than or equal to 1000h, and the shortest time t (h) is more than or equal to 100h are recorded, and the observation period is encrypted when the change rate of a certain performance index approaches 50%, so that the accurate reliability of the time t (h) is ensured.
The aging test temperature in the embodiment selects the test temperature suitable for evaluating the performance of the plastic casing material, the aging test is carried out at least 3 temperatures, the service life is obtained with the required accuracy by an extrapolation method, and the storage period of the plastic casing material indoors is quickly estimated by using the hot air aging test according to the change of the physical and mechanical properties and the like of the plastic casing material; the change of the selected performance of the plastic casing and the time for reaching the specified critical value are measured through hot air aging, the service life of the plastic casing is calculated by utilizing an Arrhenius equation diagram, scientific and reliable theoretical basis and accurate prediction result are provided, and the consumed time is short.
Specifically, in the present embodiment, the unnotched impact strength is preferably used as a reference for estimating the service life of the plastic bushing for evaluation performance.
Taking 5 plastic casing sample strips without notch impact to test the initial value of the notch-free impact strength, recording the test result and taking an average value; selecting 3 aging test temperatures according to a sample, wherein the aging test temperatures are 110 ℃, 125 ℃ and 150 ℃, and testing the change of the unnotched impact strength along with the time under the three aging temperature conditions, as shown in figure 1, drawing a corresponding diagram of the unnotched impact strength performance retention rate (%) -aging time h according to the test result, wherein the relationship of the unnotched impact strength performance retention rate y (%) -aging time x (h) is as follows: when the aging test temperature is 110 ℃, y is 2E-05x2-0.0954x + 99.628; when the aging test temperature is 125 ℃, y is 5E-05x2-0.1508x + 99.676; when the aging test temperature is 150 ℃, y is 0.0017x2-0.8432x + 89.881; from FIG. 1, the critical time at which the unnotched impact strength of the sample is maintained at 50% at the corresponding temperature can be obtained, and is shown in Table 1:
| test temperature (Absolute temperature T) | 1/T*1000 | t(h) | logt |
| 110℃(383.15K) | 2.609943886 | 594.24 | 2.773961882 |
| 125℃(398.15K) | 2.511616225 | 299.58 | 2.476512816 |
| 150℃(423.15K) | 2.36322817 | 52.95 | 1.723865964 |
TABLE 1 Critical time at 50% retention of unnotched impact Strength Property
The logarithm of the time to reach the critical value at the corresponding test temperature for the unnotched impact logt and the reciprocal of the absolute temperature of the corresponding test temperature 1/T are shown in table 2:
TABLE 2 logarithm of time to threshold logt and reciprocal 1/T of absolute temperature of corresponding test temperature
As shown in fig. 2, the logarithm of the critical time, y '(logt), to the reciprocal of the absolute temperature of the test temperature, x' (1/T), is thus derived as: y 'is 4.3218 x' -8.4578; the formula shows that the critical time at normal temperature (23 ℃), namely the service life of the plastic sleeve is 15.24 years, and the formula is shown in Table 3:
| | T | 1/T | Year | h | |
| 110℃ | 383.15 | 2.609943886 | 0.06 | 505 | |
| 125℃ | 398.15 | 2.511616225 | 0.03 | 266 | |
| 150℃ | 423.15 | 2.36322817 | 0.01 | 101 | |
| 23℃ | 296.15 | 3.376667229 | 15.24 | 131400 |
TABLE 3
Example two
The present embodiment is substantially the same as the first embodiment, except that the tensile strength is selected to be decreased to 50% of the original measured value as the critical value, and the critical value is used as the evaluation performance to estimate the service life of the casing.
Taking 5I-shaped sample strips with finished hardness for testing, carrying out a tensile strength test, recording data and averaging to obtain an initial value of the tensile strength; according to the test results of the samples, which are selected from 3 aging test temperatures (110 ℃, 125 ℃ and 150 ℃) and correspond to the change of the tensile strength along with the time, a corresponding graph of the retention rate of the tensile strength performance-the aging time h is made, and as shown in FIG. 3, the relationship of the retention rate of the tensile strength performance y (%) -the aging time x (h) is as follows: when the aging test temperature is 110 ℃, y is 2E-05x2-0.0954x + 99.622; when the aging test temperature is 125 ℃, y is 5E-05x2-0.151x + 99.679; when the aging test temperature is 150 ℃, y is 0.0017x2-0.8411x + 89.869; from FIG. 3, the critical time at which the tensile strength of the sample is maintained at 50% at the corresponding temperature can be obtained, and is shown in Table 4:
TABLE 4 Critical time at 50% retention of tensile Strength Properties
The log T of the time at which the tensile strength reached the critical value at the corresponding test temperature and the reciprocal 1/T of the absolute temperature at the corresponding test temperature are shown in Table 5:
TABLE 5 logarithm of time to critical value log T and reciprocal of absolute temperature 1/T of corresponding test temperature
As shown in FIG. 4, a plot of log T of the corresponding critical time versus the reciprocal 1/T of the absolute temperature of the test temperature can thus be obtained. Logarithm of critical time y '(logt) -inverse of absolute temperature x' (1/T) of test temperature relationship: y '4.3695 x' -8.5436; the formula shows that the critical value time at normal temperature (23 ℃), namely the service life of the plastic casing is 46.58 years; see table 6:
| | T | 1/T | Year | h | |
| 110℃ | 383.15 | 2.609943886 | 0.08 | 725 | |
| 125℃ | 398.15 | 2.511616225 | 0.03 | 270 | |
| 150℃ | 423.15 | 2.36322817 | 0.01 | 61 | |
| 23℃ | 296.15 | 3.376667229 | 46.58 | 408040 |
TABLE 6
The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.
Claims (6)
1. A prediction method for the service life of a plastic sleeve is characterized by comprising the following steps:
a. sampling: selecting a plurality of groups of sample strips of the plastic sleeve material, and measuring the initial value of the hardness (Rockwell) or tensile strength or bending strength or unnotched impact strength of the sample strips;
b. and (3) aging determination: selecting at least 3 different temperatures T (K) within the interval range of 70-200 ℃, grouping the sample strips, respectively putting the sample strips into aging rooms with at least 3 different temperatures for aging test, selecting at least 5 time nodes under each temperature condition, measuring the numerical values of the sample strips corresponding to the step a for multiple times according to the method in the step a, and recording the time point t (h) when the change rate of each performance index value of the test item point reaches 50%, wherein the time point t (h) is critical time;
c. and (3) analysis and calculation: forming a relation graph between the logarithm log T of the critical value time and the reciprocal 1/T of the absolute temperature of the testing temperature and a linear equation by using an Arrhenius equation; and calculating the storage life of the plastic sleeve at normal temperature by using an extrapolation method according to the linear equation.
2. The method for predicting the service life of the plastic casing according to claim 1, wherein in the steps a and b, if the hardness (Rockwell) value is measured, 5I-type splines are taken, 5 points are measured in each piece, and the recorded data are averaged; if the tensile strength value is measured, 5I-shaped sample strips with finished hardness are taken for testing, data are recorded, and an average value is taken; if the bending strength value is measured, 5 bending sample strips are taken for testing, and the test result is averaged and recorded; and if the unnotched impact strength value is measured, taking 5 unnotched impact sample bars for testing, recording test results and taking an average value. The hardness (Rockwell) value is measured according to the GB/T3398.2 standard, the tensile strength test is carried out according to the GB/T1447 standard when the tensile strength value is measured, the bending strength value is measured according to the GB/9341 standard, and the unnotched impact strength value is measured according to the GB/T1043 standard.
3. The method for predicting the service life of the plastic bushing as claimed in claim 2, wherein in the step b, the following 4 different aging temperatures are selected:
①, selecting a temperature of 110 ℃ (an absolute temperature of 383.15K), and respectively selecting 6 time nodes of 0h, 1560h (65d), 2016h (84d), 2496h (104d), 2592h (108d) and 2712h (113d) at the temperature for measurement;
②, selecting a temperature of 125 ℃ (absolute temperature 398.15K), and selecting 6 time nodes of 0h, 1008h (42d), 1560h (65d), 1632h (68d), 1704h (71d) and 1776h (74d) respectively at the temperature for measurement;
③, selecting the temperature of 150 ℃ (absolute temperature 423.15K), and respectively selecting 6 time nodes of 0h, 96h (4d), 168h (7d), 240h (10d), 312h (13d) and 360h (15d) at the temperature for measurement;
④, selecting the temperature of 90 ℃ (363.15K absolute), and selecting 6 time nodes of 0h, 1008h (42d), 3000h (125d), 5016h (209d), 5088h (212d) and 5160h (215d) respectively at the temperature for measurement.
4. The method for predicting the service life of the plastic casing according to claim 3, wherein in the step b, 2 groups of data are recorded for each test, and the time t (h) when the change rate of the average value of the performance indexes of the test item reaches 50% is recorded, wherein the longest time t (h) is not less than 1000h, and the shortest time t (h) is not less than 100 h.
5. The method for predicting the service life of the plastic casing according to claim 1, wherein in the step a, 5 plastic casing sample bars without notch impact are taken for testing, the initial value of the notch impact strength is tested, and the test results are recorded and averaged; in the step b, according to the test result that 3 corresponding unnotched impact strengths at the aging test temperatures (110 ℃, 125 ℃ and 150 ℃) are changed along with time, a corresponding graph of unnotched impact strength performance retention percentage-aging time h is made, and the relationship of unnotched impact strength performance retention percentage y (%) -aging time x (h) is as follows: when the aging test temperature is 110 ℃, y is 2E-05x2-0.0954x + 99.628; when the aging test temperature is 125 ℃, y is 5E-05x2-0.1508x + 99.676; when the aging test temperature is 150 ℃, y is 0.0017x2-0.8432x + 89.881; the logarithm of the critical time y '(logt) -the reciprocal of the absolute temperature of the test temperature x' (1/T) is thus derived as: y 'is 4.3218 x' -8.4578; the formula is used for obtaining the critical time at normal temperature, namely the service life of the plastic sleeve.
6. The method for predicting the service life of the plastic casing pipe according to claim 1, wherein in the step a, 5I-shaped sample strips with finished hardness are taken for testing, tensile strength testing is carried out, data are recorded and averaged, and an initial value of the tensile strength is obtained; in the step b, according to the test result that 3 aging test temperatures (110 ℃, 125 ℃ and 150 ℃) correspond to the change of the tensile strength along with the time, a corresponding graph of the tensile strength performance retention rate to the aging time h is made, and the relational expression of the tensile strength performance retention rate y (%) -the aging time x (h) is as follows: when the aging test temperature is 110 ℃, y is 2E-05x2-0.0954x + 99.622; when the aging test temperature is 125 ℃, y is 5E-05x2-0.151x + 99.679; when the aging test temperature is 150 ℃, y is 0.0017x2-0.8411x + 89.869; the logarithm of the critical time y '(logt) -the reciprocal of the absolute temperature of the test temperature x' (1/T) is thus derived as: y '4.3695 x' -8.5436; the formula is used for obtaining the critical time at normal temperature, namely the service life of the plastic sleeve.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911394802.4A CN111122343A (en) | 2019-12-30 | 2019-12-30 | Prediction method for service life of plastic sleeve |
| PCT/CN2020/134452 WO2021135852A1 (en) | 2019-12-30 | 2020-12-08 | Prediction method for service life of plastic sleeve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911394802.4A CN111122343A (en) | 2019-12-30 | 2019-12-30 | Prediction method for service life of plastic sleeve |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111122343A true CN111122343A (en) | 2020-05-08 |
Family
ID=70505031
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911394802.4A Pending CN111122343A (en) | 2019-12-30 | 2019-12-30 | Prediction method for service life of plastic sleeve |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN111122343A (en) |
| WO (1) | WO2021135852A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112560237A (en) * | 2020-12-03 | 2021-03-26 | 中国市政工程华北设计研究总院有限公司 | Method and system for rapidly testing service life of gas rubber pipe |
| CN112798507A (en) * | 2020-12-10 | 2021-05-14 | 中国船舶重工集团公司第七二五研究所 | Underwater acoustic material service life prediction method |
| WO2021135852A1 (en) * | 2019-12-30 | 2021-07-08 | 富适扣铁路器材(浙江)有限公司 | Prediction method for service life of plastic sleeve |
| CN117589663A (en) * | 2024-01-18 | 2024-02-23 | 西南石油大学 | Residual life prediction method for nonmetallic pipeline of oil-gas field |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105158085A (en) * | 2015-10-26 | 2015-12-16 | 洛阳轴研科技股份有限公司 | Compound polyimide retainer storage life prediction method |
| CN106124746A (en) * | 2016-06-15 | 2016-11-16 | 北京航空航天大学 | A kind of degraded data efficiency analysis method based on the physics of failure |
| CN109490077A (en) * | 2018-12-19 | 2019-03-19 | 北京强度环境研究所 | A kind of jet pipe rubber blanking cover accelerated storage test and life appraisal and verification method |
| KR20190126970A (en) * | 2018-05-03 | 2019-11-13 | 주식회사 엘지화학 | Method for predicting polymer properties |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111122343A (en) * | 2019-12-30 | 2020-05-08 | 富适扣铁路器材(浙江)有限公司 | Prediction method for service life of plastic sleeve |
-
2019
- 2019-12-30 CN CN201911394802.4A patent/CN111122343A/en active Pending
-
2020
- 2020-12-08 WO PCT/CN2020/134452 patent/WO2021135852A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105158085A (en) * | 2015-10-26 | 2015-12-16 | 洛阳轴研科技股份有限公司 | Compound polyimide retainer storage life prediction method |
| CN106124746A (en) * | 2016-06-15 | 2016-11-16 | 北京航空航天大学 | A kind of degraded data efficiency analysis method based on the physics of failure |
| KR20190126970A (en) * | 2018-05-03 | 2019-11-13 | 주식회사 엘지화학 | Method for predicting polymer properties |
| CN109490077A (en) * | 2018-12-19 | 2019-03-19 | 北京强度环境研究所 | A kind of jet pipe rubber blanking cover accelerated storage test and life appraisal and verification method |
Non-Patent Citations (3)
| Title |
|---|
| 李洋: "热分析法快速评估食品接触材料的使用寿命", 《中国优秀硕士学位论文全文数据库（电子期刊）》 * |
| 李茂东等: "热老化对恒定内压下PE管材性能的影响", 《塑料》 * |
| 李莹: "聚丙烯材料使用寿命预测方法", 《科技风》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021135852A1 (en) * | 2019-12-30 | 2021-07-08 | 富适扣铁路器材(浙江)有限公司 | Prediction method for service life of plastic sleeve |
| CN112560237A (en) * | 2020-12-03 | 2021-03-26 | 中国市政工程华北设计研究总院有限公司 | Method and system for rapidly testing service life of gas rubber pipe |
| CN112798507A (en) * | 2020-12-10 | 2021-05-14 | 中国船舶重工集团公司第七二五研究所 | Underwater acoustic material service life prediction method |
| CN117589663A (en) * | 2024-01-18 | 2024-02-23 | 西南石油大学 | Residual life prediction method for nonmetallic pipeline of oil-gas field |
| CN117589663B (en) * | 2024-01-18 | 2024-03-19 | 西南石油大学 | Residual life prediction method for nonmetallic pipeline of oil-gas field |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2021135852A1 (en) | 2021-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111122343A (en) | Prediction method for service life of plastic sleeve | |
| CN103063528B (en) | Method for fast evaluating high temperate member residual service life on spot | |
| CN111859658B (en) | Product storage life and reliability assessment method | |
| CN105388403B (en) | A kind of low-voltage cable remaining life quick determination method based on hardness retention rate | |
| CN107843510B (en) | Method for estimating residual endurance life of supercritical unit T/P91 heat-resistant steel based on room-temperature Brinell hardness prediction | |
| CN107563054B (en) | A kind of turbine disk life expectance analysis method of the Weakest-Link methods based on SWT parameters | |
| CN102252898A (en) | Method for testing accelerated life of electronic product based on life-stress model | |
| CN111474109B (en) | Test method for predicting service life of thermoplastic plastic in oil-gas environment | |
| CN101852701B (en) | Method for estimating long-term enduring performance of 9-12 Cr percent ferrite heat resistant steel | |
| JP6413058B2 (en) | A method for predicting flaking of concrete structures. | |
| CN109030548B (en) | Polymer material thermal aging life evaluation method based on activation energy variation | |
| CN113626970B (en) | Method and system for evaluating corrosion residual life of public pipe gallery pipeline | |
| CN111551464A (en) | Accelerated test method for testing aging performance of non-metallic material for oil and gas transmission | |
| CN112540027B (en) | Inspection and test method for modified polypropylene plastic cable protection pipe | |
| CN104914041A (en) | Aging testing method of shield tunnel elastic sealing gasket finished products | |
| CN107016247B (en) | Method for determining temperature field of dry friction surface of sample | |
| CN110411863B (en) | High-temperature creep life prediction method based on creep ductility | |
| US10634629B2 (en) | Techniques for using oxide thickness measurements for predicting crack formation and growth history in high-temperature metallic components | |
| CN106290129A (en) | A kind of calculating is in the method and system by the corrosion life of steel-cored aluminium strand | |
| CN110907287A (en) | Method for evaluating service life of composite material cable bridge | |
| CN109459320B (en) | Method for testing maximum service temperature of thermoplastic plastic | |
| Purnell | Interpretation of climatic temperature variations for accelerated ageing models | |
| CN112668156B (en) | Method for calculating storage life of nonmetallic part | |
| CN112001061A (en) | Method for estimating accelerated life of elastic non-metallic material product | |
| CN111177863A (en) | Degradation life estimation method aiming at random characteristics of mechanical wear process |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200508 |