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ASTMD4169最近对运输容器和系统的性能测试的标准实践进行了更新。卡车振动数据，配置文件和测试技术是更新的基础。以下是更新合理的摘要。

Rational for Update

近年来，ASTM D4169第12.4节中引用的卡车概况数据尚未代表从最近的卡车测量研究中收集的数据。结果，已经进行了以下更新，以反映已测量的最新字段数据。

Three primary characteristics to any random vibration profile are as follows:

1. Profile spectral shape
2. Profile intensity (Grms)
3. Profile duration (time)

1。Profile Spectral Shape:
Based upon a number of recent truck measurements throughout the Americas, the spectral shapes measured match current and widely used industry test specifications. This provides justification to cross‐reference other widely accepted Steel Spring Truck profile as the basis for the proposed ASTM D4169 truck profile spectral shape.

2. Profile Intensity:
The current measured truck data comprehensive statistical data summaries show:

• 90% of the measured data is at or below an intensity of 0.40 Grms
• 95％的测量数据处于或低于0.50 GRM的强度
• 99% of the measured data is at or below an intensity of 0.73 Grms

The update recommends conducting the test using a consistent shaped profile at varying test intensities. The following paragraphs explain the proposed levels of intensity.

Low Level ‐
The measured data indicates that 90% truck vibration occurs at a lower intensity level of up to 0.40 Grms. The update to the D4169 Truck Profile recommends testing using the proposed spectral shape starting at an intensity level that is comparable to the 90th percentile of the referenced measured data.

中等水平
The current ASTM D4169 Truck Assurance Level II profile shape is not representative of the truck environment but its intensity level—0.52 Grms—is comparable to the 95th percentile intensity level of 0.50 Grms. The update recommends testing using the ISTA Steel Spring Truck Profile at the 0.54 Grms intensity level which is slightly higher than the 0.50 Grms level and can be considered a worst case medium intensity level vibration.

High Level ‐
The measured data also contains some vibration which occurs at a higher intensity (0.73 Grms). To simulate these more intense vibration events, the update recommends testing using the proposed spectral shape with an intensity level that is comparable to the 99th percentile of the referenced measured data.

3. Profile Duration:
Currently, when performing anASTMD4169 simulationfor Distribution Cycles 1, 3, 4, 5, and 6, the truck vibration test is performed at a single intensity level (e.g. Assurance Level II) for the entire test duration. The update recommends the use of three different intensities—Low, Medium, and High—that correspond with the 90th, 95th, and 99th percentile intensities as discussed above.

The same measured vibration data used to determine the Low, Medium, and High intensity levels can also be analyzed to determine the relative amount of time that those intensity levels occur. By definition, 90th percentile (Low) intensity vibration occurs more often than the 95th percentile (Medium) intensity which occurs more often than the 99th percentile (High) intensity.

Many test labs have a historical precedent for using three‐hour test durations for ASTM D4169 vehicle vibration tests. The three‐hour test duration allows enough time for test items to respond to the test intensity and maintain an efficient time window from a test laboratory productivity perspective. To maintain that overall test duration of three hours (180 minutes), it is recommended that the truck profile spectral shapes are used at the following test intensities (levels) for a total amount of time as follows:

• Low Level:120 minutes
• 中等水平：45minutes
• High Level:15minutes

分配周期9、10、12和13需要模拟多种类型的车辆振动，并且仅建议进行60分钟的卡车测试。在其他情况下，可能有必要旋转测试项目，以使振动是不同的方向。为了适应将使用卡车振动的所有不同方式，应如下详细介绍的60分钟循环以60分钟的循环进行低，中和高测试配置文件。对于60分钟的卡车测试，只能执行一个循环。对于180分钟的卡车测试，将执行三个循环。

Note: It is important to note that there have been no modifications to the air and rail profiles and they will continue to be executed as they have in the past.

Note: The rational provided with the ballot was used as a basis for this document.