A Guide to Dynamics Test Methods

Dynamics testing evaluates components in high-stress, high-performance environments.  通常，这些环境模拟了在预期平台上可能遇到的实际情况，并添加了边际. 部件在实验室条件下进行测试，以评估它们如何应对不同程度和类型的振动, 冲击, 压力, 噪音, 还有其他力量.

介绍

动态测试不仅对认证至关重要，而且在产品开发和认证前的概念验证中也起着关键作用. 另外, 这对于满足商业航空标准的严格要求至关重要 RTCA / - 160 and military qualification standard MIL-STD 810.

These test methods can also be applied to post 认证 issues, 一旦组件已经在现场，就对发现的异常进行基准测试. By accurately reproducing and then repeatedly simulating the damage, the design of the component can then be modified appropriately. This sort of testing is therefore essential in the design, 发展, 认证, and qualification of components across the 航空航天, 国防, 船上, 铁路, and automotive industries; testing products 如 fan blades, 燃料系统, 传感器, 机体系统, 涡轮发动机部件, 燃烧器, 泵, 和阀门, 等. A fan blade off event in a turbine engine, 例如, 是否会造成严重的不平衡和振动，从而有可能对整个航空结构造成灾难性的破坏. 

执行动态测试以确保产品不受今天使用的运输方法的影响也是至关重要的. 运输过程中产生的冲击和振动会影响产品的可靠性, 效率, 或者整体寿命. 

im体育APP的动态测试组合涵盖了广泛的测试程序，包括冲击测试, high level reverberant acoustic 噪音 testing, 线性/角加速度测试以及全方位的振动测试程序：

振动测试

There are several different types of vibration test procedures, so understanding each method’s approach and benefits is key when selecting a method. 该方法应能够复制产品或组件的环境条件和现场振动（可以是结构或空气传播）. 

关键方法 振动测试 包括: 

• 电动测试 部件在低位移（4英寸DA） /高频振动电平（3000Hz）. im体育APP’s testing facilities worldwide go up to a maximum of 44,000 force pounds.

• 水动力测试 of components at a high displacement (16-inch DA, low frequency (0-500HZ) vibration, simulating extreme environmental conditions, 比如地震, aircraft fan blade off / tire burst.

• 压电测试 用于测试超高频率（40-50KHz）的部件，例如涡轮风扇叶片.

• Sinusoidal (Sine) 振动测试 是否多次用于确定试样的结构（共振）临界频率.  This sinusoidal tone can be swept across the test frequency range, or it can be fixed on a single frequency, 视需要而定. Many times after the critical frequencies are identified, a frequency dwell follows at these frequencies to put the test item under maximum loads.

• 随机振动程序 掩盖由运输或操作环境（如飞机）引起的随机性质的振动, 空间飞行器, 陆地车辆. Random vibration replicates environments that are unpredictable and non-repetitive. 不像正弦方法, 这依赖于稳定, regular frequency for testing, these methods use uniquely generated patterns to simulate real-world applications. 

Sometimes more than one type of method is used, combining multiple vibration methods 如 sine-on-random and random-on-random, to create a single composite standard. 这可以帮助满足项目的要求，以确保准确的测试条件或创建一个加速程序. 

冲击测试 

冲击测试 includes 冲击 response spectrum (SRS), 半正弦, 端峰锯齿, 热冲击模拟, 以及弹道测试, all of which prepare products for harsh industrial, transportation and military environments. By measuring the impact of sudden acceleration caused by drop or collision, 冲击测试能够确保产品能够满足各种工业和军事标准, 包括RTCA DO-160, mil - std - 810, DEF STAN 00-35和EN 60068.

加速度 

Mainly used by the 航空航天 industry, 线性加速度测试通常利用离心机来模拟在飞行中使用的设备或部件上产生机械载荷的重力. im体育APP使用不同的力和速度来重现重力的显著变化, including altitude changes and crash scenarios.  

High level acoustic 噪音 testing

Carried out in specialized reverberant chambers, high level acoustic 噪音 tests simulate high level airborne induced vibration. 航空航天和其他工业部件暴露在这种强烈的声压下, helping to meet military acoustic testing specifications, 如 mil - std - 810方法515.

Combining multiple test types into a single testing program

Highly Accelerated Life 测试 (停止测试)和高加速应力筛选（HASS测试）能够结合非常快速的高温和低温循环（高达60度）. C / minute) with high level random vibration (up to 70 GRMS).

停止测试 is frequently used in R&设计验证以在问题出现之前预测问题，并避免在全面测试中可能发生的代价高昂的错误, 或者在现场. HALT and HASS testing are also used to test finished components, 模拟真实世界的条件，在产品投放市场之前发现隐藏的缺陷. By monitoring system performance throughout the testing process, im体育APP can provide crucial details about structural vulnerability, 热的反应, 使用寿命, 和更多的. 

Key considerations when preparing to test 

充分准备测试将有助于最大限度地提高组件第一次通过动态测试程序的机会，因为失败并不总是由于测试项目本身.  与非测试项目相关的失败最常见的原因之一是夹具设计不良, leading to the over or under testing of the unit. 

准备测试时, it is vital to pay due consideration to the design of the test fixture, which usually requires carefully duplicating the normal means of mounting. If the component will require a ridged mount, or a mount that replicates an installation with a degree of flexibility, 也应该确定.  

测试前要问的另一个关键问题是，测试期间是否需要操作被测设备（UUT）, 如果是这样的话, what will be the definition of the operation as well as the pass / fail criteria. 此时此刻, 在测试期间，评估UUT上是否有您想要测量的关键区域（如加速度计或应变计）是很重要的.

还应确定在适当输入水平下进行测试的正确区域和类别. If electrical operation is required, 设计应包括从测试项目到试验台的合适电缆长度. This is a common oversight that frequently causes testing to be delayed. 同样, if hydraulic or pneumatic operation is required, 在测试时，适当的连接不会给测试项目带来机械负荷，必须纳入设计.  

Building a comprehensive test plan with im体育APP

im体育APP的动力学专家团队可以根据您的具体需求制定全面的测试计划, combining multiple test methods to create a single, complete program that ensures product safety while saving time and money.

Working with the manufacturer, 我们将在组件或产品生命周期的每个阶段为其设计理想的测试方案, 指导制造商完成设计过程，并在安装和固定等问题上提供宝贵的经验和专家建议. 测试之后, 提供详细的专业测试报告，可包含在认证包中. 

im体育APP广泛的全球产能为制造商提供了最高的振动测试能力，以满足测试要求, allowing a high level of scheduling flexibility. 该公司在全球范围内的设施包括一些用于冲击和振动测试的最大动态系统，以实现对大尺寸产品的测试, 重心高, 和抵消负载.

For more information about dynamics testing, please contact our product qualification experts.