Expertise Facility Types

Research tagged "hammer testing"

Voids Beneath Slabs-on-Ground: Using the impulse response test to verify adequate slab support

Introduction A concrete slab-on-ground is one of the most common of all floor types.  Slabs-on-ground are popular for many applications, especially in research facilities, where they usually provide the highest-quality vibration environment.  This is because they are stiff and uniformly supported, such that they do not exhibit the resonance characteristics of a suspended slab. As […]...
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Meeting The Vibration Challenges Of Next-Generation Photolithography Tools

In the past, the vibration design process has been driven by the requirements for an acceptable ambient vibration environment for tools. However, the newest generation of photolithography tools, the "scanners" or "step-and-scan" systems, impose an additional requirement for the dynamic resistance properties of the tool's support points. This paper discusses the current scanner support criteria […]...
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Dynamic Characteristics of Structures Extracted from In-situ Testing

The paper discusses two primary areas of interest in a structural evaluation. First, in-situ measurements are used to confirm the predicted structural stiffnesses and resonance frequencies. Second, the evaluation characterizes the manner in which vibrations are propagated through the structure. Methodologies are presented for carrying out these measurements, and typical data are given. H. Amick, […]...
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