1 简单的介绍
1.1 This test method includes the evaluation method of the tensile properties of vulcanized thermoset rubber and thermoplastic elastomer. This test method cannot be used to test hard glue and materials with high hardness and low elongation. 测试方法如下:

方法A – Straight bars and dumbbell specimens

方法B — 环形标本

笔记 1 -The results of the two tests are not comparable.

1.2 基于 SI 或非 SI 的单位被视为本标准的标准单位. Since the value of the results may be different when using different unit systems, 不同单位应单独使用，不得混合使用.

1.3 安全

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

2 参考
D 1349 橡胶规格 — Standard temperature for testing

D 1566 Rubber related terms

D 3182 橡胶规格 — 材料, equipment and procedures for the preparation of standard compounds and standard vulcanized test sheets

D 3183 橡胶规格 – Preparation of test sheets from finished products

D 4483 Specification for measuring accuracy of standard test methods for rubber and carbon black industrial varieties

2.2 ASTM Accessories

环形试样的制备, method B

2.3 国际标准化组织标准

国际标准化组织 37 – Determination of tensile stress-strain properties of vulcanized or thermoplastic rubber

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

3 术语
3.1 定义

3.1.1 拉伸长期变形 — the residual deformation of the specimen after elongation under certain action, when the action force is relieved, 表示为原始长度的百分比.

3.1.2 Tearing long deformation — the long deformation measured by attaching the broken dumbbell sample to the cross section.

3.1.3 拉力 — the maximum force generated in the process of specimen breaking.

3.1.4 抗拉强度 — the stress used to stretch the specimen

3.1.5 恒定的延伸应力 — the stress generated when the specimen of regular section is stretched to a specific length.

3.1.6 Thermoplastic elastomer – A material similar to rubber, 但与普通硫化橡胶不同, 它可以像塑料一样被加工和回收.

3.1.7 断裂伸长率 — the elongation rate of the specimen when it breaks during continuous stretching.

3.1.8 屈服点 — the point on the stress-strain curve where the velocity of stress change with respect to strain becomes zero and opposite before the final failure of the specimen.

3.1.9 屈服应变 — 屈服点的应变水平

3.1.10 屈服应力 — 屈服点的应力水平

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

4 Method description
4.1 Test to determine the tensile properties, first cut the sample from the sample material, including sample preparation and test two parts. The shape of the sample can be dumbbell, 环或直条, 且断面形状规则.

4.2 Test the tensile strength, 固定应力, 没有预先拉伸样品的屈服点和断裂伸长率. 拉伸强度的测定, 固定应力, yield point and elongation at break of the specimen with regular section is based on the original cross-sectional area of the specimen.

4.3 Long term deformation by stretching and long term deformation by tearing. Measure the deformation of the sample after drawing back according to the specified method.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

5 Key points and applications
5.1 本次测试涉及的材料或产品在实际应用过程中需要承受拉力. This test is to determine such tensile characteristics. 然而, the tensile performance does not directly represent the whole situation of the final use of the product, because the product needs to cover a wide range of potential uses in actual use.

5.2 Tensile properties are related to materials and test conditions (拉伸速度, 测试温度和湿度, 样品几何形状, 预测试调整, ETC。). 所以, 相同条件下材料的测试结果具有可比性.

5.3 Test temperature and tensile speed have significant influence on tensile properties, 应该严格控制的. And the effect varies with the material.

5.4 拉伸长期变形代表样品的残余变形. 代表样品拉伸和回缩后的长期变形和部分恢复. 所以, 拉伸和收缩过程 (以及其他测试条件) need to be tightly controlled to ensure that the results are comparable.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

6 设备
6.1 拉力机 — The tensile testing machine shall have an electric drive mechanism to ensure that the separation speed of the sample chuck is constant at 500±50mm/min and the minimum stroke is 750mm(看注释 1). The test machine should have a set of suitable dynamometer and reading recording system to ensure that the measured force deviation is within ±2%. 如果无法改变试验机的量程 (例如, 摆式测功机), then the deviation of the force measured when the specimen breaks is ±2% of the full range of the dynamometer, and the accuracy of the minimum force measured is 10%. If the dynamometer has an automatic compensation function for the direct measurement of tensile stress, the compensation function for the cross-sectional area of the specimen junction should be turned off during the measurement. The recording device should be fast enough to measure the force and ensure the required accuracy during the whole process of specimen destruction. If the tester does not have a recording device, there should be an indicator to indicate the maximum force during the stretch. 伸长率应在测试系统中测量，最小增量为 10%.

笔记 1 — 如果使用的拉伸速度为1000±100mm/min, 应在测试报告中注明. If in doubt, the test should be rerun at a speed of 500mm/min.

6.2 High and low temperature test chamber – The test chamber shall meet the following requirements:

6.2.1 在测试室中, there should be a heat flow around the position of the chuck and shaft, 环绕速度为 1 至 2m/s, and the temperature should be kept within the range of 2℃ of the required temperature deviation.

6.2.2 Apply the calibrated temperature measuring device to measure the actual temperature near the chuck and shaft.

6.2.3 The test chamber shall have an exhaust ventilation device to discharge the gas released in the high temperature (样本) to the atmosphere.

6.2.4 测试前, 样品应垂直放置在卡盘和轴附近以便调整. Specimens should not be in contact with each other or with the walls of the test chamber except for momentary contact caused by agitation of the surrounding air.

6.2.5 Place the chuck appropriately to facilitate operation in high and low temperature environment. 这样, the dumbbell or straight strip specimen is placed into the chuck for as short a time as possible to reduce the temperature change of the test chamber.

6.2.6 The dynamometer shall be suitable for working at the test temperature or be well insulated from the test chamber.

6.2.7 The test chamber shall be equipped with elongation measuring device. If a ruler is used to measure the elongation of the sample scale, the ruler should be placed parallel to the scale close to the path of the chuck and can be controlled from outside the test chamber.

6.3 Thickness Gauge — The thickness gauge shall meet the requirements of Specification D 3767(方法A). 对于环形样品, 见文章 14.10 该测试方法的.

6.4 拉伸长期变形的测量 — using test equipment as described in 6.1 或如图所示 1. The measuring range of stopwatch or other timing device should be greater than 30min, and the measuring accuracy of ruler or other measuring device should be within 1%.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

7 样品的选择
7.1 The following points should be considered when selecting the sample

7.1.1 During preparation and treatment, the anisotropy and orientation of the material caused by the flow can affect the tensile properties. 所以, in the preparation of dumbbell or straight strip specimens, on the premise of knowing the calendering direction, 样品切割方向应与压延方向平行. 对于环形样品, it is usually made a certain average of the orientation characteristics.

7.1.2 For thermoplastic rubber or elastomer, samples shall be cut from injection molded samples with a thickness of 3.0±0.3mm, and the test results obtained from samples with other thicknesses shall be comparable, 除非另有规定. Samples should be perpendicular and parallel to the forming flow direction of two groups. The size of the test piece or plate should meet the test requirements.

7.1.3 The elongation of annular specimens can be measured by the separation of collets, but the elongation distribution on the radius and width of specimens is inconsistent. 为了减少这种影响, the sample width should be less than the diameter of the annular sample.

7.1.4 In the ordinary tensile test with small straight strip specimens, the failure of the specimens generally occurs in the chuck. 所以, only when the sample can not be made of other shapes of the sample to use the straight sample. For non-destructive stress-strain or material modulus tests, straight strip specimens are used.

7.1.4 样品的大小取决于材料的要求, 测试设备和测试所用的样品. 对于断裂伸长率低的材料, longer specimens can be used to improve the accuracy of measuring elongation.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

8 测试设备的校准
8.1 Calibrate the tester according to Procedure A of Specification E 4 for measuring precision type dynamometers, and calibrate one or more force points according to section 7 和 18 of specification E 4. For the pendulum dynamometer, 请按照以下步骤进行校准:

8.1.1 将哑铃样品的一端放入试验机的卡盘中.

8.1.2 从试验机上拆下下卡盘, 也就是说, the gripping mechanism of the sample is on the upper chuck of the testing machine.

8.1.3 下卡盘上安装挂钩，用于固定样品下端

8.1.4 Hang a weight of known weight to the hook, so that a certain mass can be temporarily applied to the lower fixture of the specimen (看注释 2).

8.1.5 Open the monitoring device for jig movement, and keep it running continuously until the weight is free to hang on the sample in the ordinary test.

8.1.6 If the disc or ruler (or the equivalent of a stress compensator) does not indicate the force value within the specified accuracy, the equipment shall be effectively checked for faults (例如. friction of shafts or other moving parts). 应确定下卡盘和吊钩的质量也被考虑在内.

8.1.7 试验机摩擦等故障排除后, calibrate the testing machine to know that the weights are measured at three points at about 10, 20 和 50% 试验机的满量程. If ratchets and spines are used in normal tests, they should also be used in school. Friction is checked by installing a ratchet.

笔记 3 — There shall be a device to prevent weights from falling from the test machine.

8.2 可使用弹簧进行近似快速校准.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

9 测试温度
9.1 除非另有规定, 标准测试温度为23±2℃. 样品应调整为 23 °C 至少 3 小时. 如果材料受湿度影响, 样品应在 50±5%R.H 下调节. 超过 24 考试前几小时. 如果在其他温度下测试, 规范 D 中列出的温度 1349 应使用.

9.2 If the test is conducted at A temperature higher than 23℃, A法样品需预热10±2min; For method B, it should be preheated for 6±2min. 在每个测试间隔之前, the specimens are placed separately in the test chamber so that all specimens receive the same warm-up time continuously. Preheating tests at high temperatures should be strictly limited to prevent persulfur and thermal aging.

笔记 3 — 警告: 除其他警告外, use insulated and cold gloves to protect hands from high and low temperatures. 高温实验时应佩戴口罩，防止打开实验箱门时吸入有毒气体.

9.3 用于低温测试, 样品应预冷至少10分钟.

测试方法A — Strips and dumbbell specimens

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

10 设备
10.1 Cutting Tool — The shape and size of the cutting tool should conform to that shown in Figure 2. The inside of the narrow part of the cutting tool shall be perpendicular to the end face of the cutting tool, and at least 5mm long from the end face of the cutting tool shall be polished. The shape of the cutter should remain unchanged without defect. (看注释 4)

笔记 4 — 通过观察样品的断裂点可以确定切削刀具的状况. The fractured specimens were removed from the chuck and spliced along the fracture surface to observe whether the failure of the specimens occurred at the same location. 如果故障发生在同一位置, the cutter may become blunt, 有缺陷的, 或者在这个位置弯曲.

10.2 Marking — Two marking lines drawn on the specimen for measuring elongation and strain are called marking (看注释 5). The line marker shall include a flat plate with two bumps parallel to each other. 凸起的表面 (与板表面平行) 应该有一个狭长的平面, 并且两个面应保持在同一平面上. 凸出的平面是 0.05 宽至 0.08 毫米，长至少 15 毫米. The Angle between the plate and the bump should be at least 75º. 两凸面中心距应保持在 1% of the deviation of the required or target distance. A handle shall be included on the back or top of the line marker.

笔记 4 — No marking is required if contact extensometers are used.

Ink Marking — 使用平板, 硬表面 (硬木, 金属, 或塑料) to make ink or toner marking. The ink or toner shall be firmly bonded to the specimen, shall not corrode the specimen, and shall contrast with the color of the specimen.

10.4 Collets — 测试仪有两个夹头, 其中之一连接到测功机.

10.4.1 The chuck of the test dumbbell sample shall have a self-tightening device to generate constant pressure on the surface of the chuck. With the increase of elongation, the clamping force shall also increase to prevent sliding and make the failure occur in the narrow part of the sample. A constant pneumatic chuck is also suitable. There is a special part in the broken part of the fixture, so that the length of the sample inserted into the fixture is the same and the stress distribution is uniform.

10.4.2 The fixture used for testing straight strip specimens shall have pneumatic fixture, 夹口或螺栓扣, so that the clamping force of the fixture can be uniformly applied to the entire width of the sample.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

11 样本
11.1 哑铃标本 — 只要有可能, specimens shall be injection molded or cut from specimens 1.3 厚至3.3毫米. One test method can be used to cut the thickness and size of the specimen (see specification D 3182). 试件可直接制作或由成品切割抛光. If the specimen is prepared directly from the finished product, 表面不应是硬质皮革或织物, ETC. According to the requirements of Specification D 3183. All specimens should be cut parallel to the length of the specimen unless otherwise specified. 如果样品按照规范 D 制备 3182, 其厚度应为2.0±0.2mm，并沿材料的方向切割. Use a C-type cutter (如图. 2) with a simple stamping device and ensure smooth cut surface. .

11.1.1 标记哑铃标本 — The dumbbell specimens shall be marked as described in 10.2, and the specimens shall not be subject to tension when the lines are marked. The mark should be drawn in the narrow part, equal distance from the center of the specimen and perpendicular to the vertical axis. The distance between the two lines is 25.00±0.25mm for type C and type D samples; Others 50.00±0.5mm

11.1.2 Dumbbell sample thickness measurement — The sample thickness should be measured at three points, one point in the center and two points at both ends of the narrow part. The median of the three values was taken to calculate the cross-sectional area. 如果样品厚度的范围大于 0.08, the sample is invalid. 样品的宽度可根据刀具工作部分的宽度计算.

11.2 直条状试样 — if dumbbells or annular specimens cannot be cut from the sample, 直条状试样 (例如. narrow bands, 小管, or fine electrical insulating materials) may be cut. 样本应足够长以适合夹具. The scale spacing is 11.1.1. 计算管的测试横截面积, 质量, 应使用管的长度和密度. 横截面积计算如下:

在哪里:

A=横截面积,平方厘米

M=质量,G

D=密度,克/立方厘米

L=长度,厘米

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

12 脚步
12.1 拉应力的测定, 抗拉强度和屈服点 — 将哑铃样品装入试验机的夹具中, and pay attention to adjust the symmetry of the sample clamping, 使拉力均匀分布在样品截面上. 这将避免高估样本的拉力. The test speed was 500±50mm/min(看注释 7) 除非另有规定. Start the test machine and pay attention to the line marking to prevent the influence of parallax. The force values at special elongation and at fracture were recorded. Elongation can be measured using an extensiometer, an automatic drawing, or an optical tracking system. 断裂伸长率测量精度在 10%. 看 13 用于计算.

笔记 8 — 如果样品的屈服点低于 20% 试验速度500±50mm/min时的伸长率, 测试速度可降低至50±5mm/min. 如果样品的屈服点仍低于 20% 伸长, 测试速度可降低至5±0.5mm/min. Sample speed shall be recorded.

12.2 拉伸长期变形的测定 — Load the specimen into the testing machine or device described in 6.1 如图 1. Pay attention to adjust the gripping symmetry of the sample so that the tension is evenly distributed on the sample section. The speed of chuck separation should be as constant as possible, so that the time to reach the specified elongation is 15s, and maintain this elongation for 10min. 10分钟后, the load was released immediately and allowed to recover freely for 10min. 在那之后, the residual deformation within the standard distance was measured with a measurement accuracy of 1% 原来的距离. Use a stopwatch to record the time. 看 13 for calculation

12.3 Determination of long-term fracture deformation — 样品破碎10min后, carefully splice the sample and measure the residual deformation within the standard distance, as shown in 13

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

13 计算
13.1 任意伸长时的强度计算:

(2)

在等式中

时间(XXX)= 伸长强度 (XXX)%,兆帕

F(XXX)= 比伸长率时的应力,明尼苏达州

A= sample cross-sectional area,平方米

13.2 屈服强度的计算

(3)

在等式中

是(压力)= 屈服强度,兆帕

F(y)= 屈服力,明尼苏达州

A= sample cross-sectional area,平方米

13.3 The evaluated yield point is the point on the stress-strain curve where the velocity of stress change with respect to strain becomes zero and opposite before the final failure of the specimen.

13.4 拉伸强度的计算

（4）

在等式中

TS=拉伸强度,兆帕

F(是)= maximum force at break,明尼苏达州

A= sample cross-sectional area,平方米

13.5 Calculate the elongation rate at any elongation;

（5）

在等式中

E= 伸长率 (比例距离),%

L=样本标准距离内的观测距离,毫米

L(0)= original scale length of the sample,毫米

13.6 Elongation at break is calculated by substituting L when the sample breaks into Equation 5.

13.7 公式 5 can also be used to calculate the long-term deformation, as long as L in the formula is substituted with the residual deformation after 10min.

13.8 检测结果 — 测试结果表示为三个独立连续样品结果的中位数. 分两种特殊情况, 测试了五个样品并报告了五个样品的中值.

13.8.1 特例 1 — When the results of one or two specimens in the test do not meet the specially required measurements.

13.8.2 特例 2 — for arbitral trials.

方法B — 环形标本

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

14 设备
14.1 刀具 — Annular cutter is shown in Figure 3. Use a cutting knife to cut an annular specimen from a flat specimen, and install a part of the upper shaft of the cutting knife into a rotary compression device under which the specimen can be fixed to a rubber fixing device.

14.1.1 刀片深度保持器 — The cylindrical disc in the retainer shall be at least 0.5mm thicker than the thickness of the rubber sheet to be cut. Its diameter should be less than the inner diameter of the sample, 以便可以从切割工具上调节刀片的突出量. 见图 3

14.2 橡胶固定板 — a device for holding rubber in place during cutting, with top and bottom surfaces parallel to each other, made of hard polymeric materials (硬胶, 聚氨酯和聚甲基丙烯酸甲酯). The holes, about 1.5mm in diameter, are distributed 6 to 7mm apart in the center through the plate. All these holes should communicate with the mold cavity inside to reduce the air pressure used to hold the test piece. 数字 4 is used to clamp the standard test piece (约150×150×2mm) 切割过程中.

14.3 气压源 — A vacuum pump can be used to maintain a suction force of 10kPa on the sample at the center of the gripper mold cavity.

14.4 Soapy Water — Use neutral soapy water to lubricate the cutter.

14.5 旋切 — The test piece can be cut by a precision rotary hole machine or other equipment that can provide at least 30rad/s speed. The cutter rotation device shall be mounted on a horizontal plane with a vertical positioner to support the rotating connecting rod and the shaft used for the cutter. 转轴偏心距应小于0.01mm.

14.6 Built-in workbench — There shall be a workbench or other device that can move along the x-y axis respectively for gripping and positioning the test piece so that the test piece corresponds to the rotational axis of the rotating cutter.

14.7 Tensile testing Machine — shall meet the requirements as described in 6.1.

14.8 测试治具 — The fixture of the annular specimen is shown in Figure 5. 试验机应按下列规定进行校准： 8 rules.

14.9 Test Chamber — The high and low temperature test chamber shall meet the requirements in 6.2.

14.9.1 夹具不仅应适合在室温下进行测试. 然而, 特殊温度下, 应采用适当的润滑，保证转轴的润滑.

14.9.2 测功机应适合在工作温度下使用或与试验室绝缘良好.

14.10 测厚仪 — Thickness gauges shall comply with the requirements of Specification D 3767(方法A).

14.10.1 The main part of the thickness gauge, 圆柱形上测量表面 (vertical axis along the vertical direction) 高至少12mm，直径至少15.5±0.5mm. In order to be suitable for small annular samples, a measuring head with a diameter of 15.5mm is used to measure, 并且测量不会引起样品的伸长. The bottom of the cylindrical surface can be cut off half along the center, so that there is no interference when measuring small samples. 也可以使用弯曲的测量端.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

15. 环形标本

15.1 ASTM 环形试样 — 有两种类型. 一般来说, 1-shaped specimens are used

15.1.1 样本量

类型 1

The inner circumference was 50.0±0.01mm

内径15.92±0.003mm

The radial width was 1.0±0.01mm

Thickness 1.0~3.3mm

类型 2

The inner circumference is 100.0±0.2mm

内径29.8±0.06mm

Radial width 2.0±0.02mm

Thickness 1.0~3.3mm

15.2 ISO 环形试样 — There are two types of specimens, ordinary and small, 根据ISO 37, 其中规定了其具体的测试程序.

普通的

Inner diameter 44.6±0.2mm

Outer diameter 52.6±0.2mm

Thickness 4.0±0.2mm

小尺寸

内径8.0±0.1mm

外径10.0±0.1mm

Thickness 1.0±0.1mm

15.3 从管道上切下环形样品 — the diameter wall thickness of the annular sample shall be absolutely the wall thickness of the pipe and shall meet the requirements of the product.

15.4 切割样品的制备 — Place the blade in the holder of the cutting tool and adjust the depth of the blade. 将刀具放入旋转压力机中，调整轴或工作台，使刀架底部高出样品托板13mm. Shrink the stop for vertical movement of the rotating shaft. This allows the end of the blade holder to penetrate the surface of the plate. Put the sample into the gripper and reduce the pressure of the chamber to 10kPa. 用中性肥皂水润湿试件表面. The cutter should be reduced at a constant speed and then stopped. 此时, the cutter holder should not touch the test piece. Re-adjust the blade depth if necessary. Reset the rotating shaft before the next cutting.

15.5 Preparation method for cutting a sample from a pipe — insert a shaft into the pipe, the diameter of which is slightly larger than the pipe diameter. Put the shaft and tube together on the machine tool. Cut the sample of the required axial thickness from the sample with the blade or cutter on the machine tool. For thin-walled pipes, a cutter with two parallel blades can be used to cut them flat.

15.6 环形标本:

15.6.1 Circumference — The inner circumference can be measured with a cone or a gauge. 测量过程中不能用应力改变环形试样的椭圆度. 中值周长可以基于内周长, the meridional width and π(3.14).

15.6.2 径向宽度 — three measuring points are evenly distributed around the circumference of the specimen according to the thickness gauge in 14.10.

15.6.3 厚度 — When cutting annular specimens, the thickness of the disk from inner circle to outer circle can be measured by thickness gauge according to specification D 3767.

15.6.4 横截面面积 – The cross-sectional area was calculated as the median of three measurements of radial width and thickness. 适用于薄管壁样品, the cross-sectional area was calculated using the axial length of the cutter and the wall thickness.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

16 过程
16.1. 拉应力的测定, 抗拉强度, 环形试样的断裂伸长率和屈服点 — 通过润滑装置对轴进行适当的润滑, 例如矿物油或硅油. Should choose to use the prescribed and no impact on the material. 两个夹具轴心初始位置的计算和调整如下:

(6)

在哪里:

IS= initial distance from the center of the jig shaft,毫米

C(TS)= circumference of the sample, 对于类型 1 样品是内径, 对于类型 2 样本是直径,毫米

C(SP)= circumference of jig shaft,毫米

The test speed was 500±50 mammin (see notes 7 和 8), among other requirements. Start the test machine and record the force and the relative displacement of the two jig shafts. Elongation and stress were recorded at break. The calculation is shown in Section 17,

笔记 8 — The test speed was 100±10mm/min using ISO small ring type sample.

16.2 非标准温度下的实验 – 按照中所述使用测试室 6.2 and read the warnings in Note 2. For tests above 23 °C, 样品在此温度下预热6±2min. 用于低于室温的测试, 样品应在该温度下调整至少10分钟. 测试温度D 1349 应该使用. The test pieces shall be put into the test chamber separately to meet the requirements of 9.2.

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

17 计算
17.1 除了一点很重要, the calculation of the stress-strain properties of the ring-shaped specimens is the same as that of the dumbbell or straight strip specimens. 当环形试样被拉伸时, the stress distribution of each edge of the annular is not uniform in width (从左到右). The initial inner diameter of the sample is less than the initial outer diameter. 所以, in the tensile test of the specimen, the stress of the inner test is greater than that of the outer test, which is caused by the difference in the initial size.

17.2 The following options can be used to calculate tensile strength and fracture strength.

17.2.1 Constant elongation stress — use the median circumference of the annular specimen to calculate the elongation. The reason for using the median perimeter is that it corresponds to the average of the edges of the annular specimens.

17.2.2 断裂伸长率 — 以环形试件的内周长作为计算依据, as it corresponds to the maximum stress at each edge of the specimen. This position is also the starting position of sample failure.

17.3 恒定延伸应力根据方程计算 2 在 13.1

17.3.1 用于确定方程中的力的伸长率 2 (13.1) 计算如下

(7)

在哪里:

E=伸长率,%

L= increase in distance between fixtures,毫米

MC(TS)= 样品的中值周长,毫米

17.3.2 In Formula 7, the distance between fixtures during fixed extension is calculated by the following formula:

(8)

17.4 屈服点根据方程计算 3 在 13.2

17.5 Determine the yield stress according to 13.3. 由于屈服应力是用来评价材料的综合性能, 中位周长用于计算.

17.6 Calculate tensile strength according to Equation 4 在 13.4.

17.7 Elongation at break is calculated according to the following equation (见注释 9 和 10)

(9)

在哪里:

E=断裂伸长率,%

L= increased distance of fixture at break,毫米

我知道了(TS)= 图案的初始内周长,毫米

17.8 The inner perimeter can be used for two types of specimens (看 15.1.1 方面). 内周长类型 2 环形样本使用内径计算.

笔记 9 — 方程 7 和 8 can be used only when the initial spacing of the fixture is adjusted according to Equation 7.

笔记 10 — Caution should be taken when using this method because stresses at elongation slightly below the elongation at break (4 到 5%) may not be calculated when different dimensions are used to calculate 1) 恒定伸长应力 (小于断裂应力) 和 2) 断裂伸长率 (看 20.1 和 20.2).

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

18 报告
18.1 The report shall contain the following contents:

18.1.1 Calculation results based on Section 13 或者 17

18.1.2 样本类型和描述, 按13节刀具类型, 在美国, 自制或公制单位

18.1.3 Experiment date

18.1.4 测试速度

18.1.5 实验室温度、湿度

18.1.6 测试温度 (如果不是23±2℃)

18.1.7 If possible, date of vulcanization or/and rubber preparation

ASTM D412-0 硫化橡胶和热塑性弹性体拉伸试验方法

19 偏差精度 (省略)

20 关键词 (Omitted)