Effective mass models are a powerful framework in mechanical design and qualification. They are a specialized modal model that use a base-acceleration input to yield the response of a base-mounted structure in single-axis dynamic environments. Applications include the computation of reaction forces of each mode of the base-mounted payload, the identification of the most “important” modes for loads analysis, and many others. Originally derived from a finite element model of the structure, many experimental techniques for computing effective mass models have also been developed. This work describes the derivation of a novel technique which utilizes the Craig-Bampton Modal framework to extract an effective mass model from a modal test and provides a much simpler formulation than previous methods while maintaining the accuracy of the computed effective mass model. Analytical and experimental demonstrations are provided along with practical recommendations for successful implementation.

有效质量模型是机械设计和鉴定的强大框架。它们是一种专门的模态模型，使用基础加速度输入来产生单轴动态环境中基础安装结构的响应。应用包括计算底座有效载荷每种模式的反作用力、识别负载分析最“重要”的模式等等。最初源自结构的有限元模型，还开发了许多用于计算有效质量模型的实验技术。这项工作描述了一种新技术的推导，该技术利用 Craig-Bampton 模态框架从模态测试中提取有效质量模型，并提供比以前的方法更简单的公式，同时保持计算的有效质量模型的准确性。提供了分析和实验演示以及成功实施的实际建议。