Variable Mode Shape High-Frequency Force-Balance

与乘员舒适度相关的正常使用极限状态 风引起的横向和扭转运动正变得越来越重要， 这是高层建筑设计中的重要考虑因素。 在一些 在某些情况下，需要进行结构修改以产生可接受的 预测的响应特性可以花费数百到数千个 美元，甚至数百万美元。 在这样的代价下 预测的反应水平必须准确， 尽可能可靠。 气动弹性模型试验和高频力平衡试验提供了 估计建筑物对风的响应的两种方法。 在大多数情况下， 气动弹性模型试验是不切实际的，因为需要时间， 设计和构建模型。 完成后取得的成果 正常设计过程可以产生复杂的修改或生动的 居住者必须忍受无数次干扰的建筑物 议案 目前高频力平衡测试可以提供结果 在气动弹性模型试验所需时间的一小部分内， 结合了用于摇摆线性振型和用于 扭转 力平衡测试也不能提供以下信息： 可能的气动弹性效应可能增加或减少载荷， 反应 提出了第二代高频测力天平的研究方向 以及相关的仪器， 通过允许确定各种模式的模态力， 形状. 最后，提出了建筑物对环境影响的研究方向 模态力的运动 主要研究者具有良好的资质， 进行研究。 这项研究将改善力量平衡 用于商业风洞测试实验室。 使用 改进的平衡将允许更准确地预测风引起的 复杂结构的响应，其中扭转是重要的 考虑和模式形状不是线性的。 更好 对气动弹性效应的了解将提供有价值的信息 关于应用和力平衡测试的限制

The serviceability limit state associated with occupant comfort under wind induced lateral and torsional motion is becoming an increasingly important consideration in the design of tall buildings. In some instances, structural modifications required to produce acceptable predicted response characteristics can cost hundreds for thousands of dollars or even millions of dollars. With these kinds of cost at stake it is imperative that predicted response levels be as accurate and reliable as possible. Aeroelastic model tests and high-frequency force-balance tests provide two means of estimating building response to winds. In most instances, aeroelastic model tests are impractical because of the time required to design and construct the models. Results obtained after completion of the normal design process cn produce cotly modificaiton or lively buildings where occupants must endure numerous instance of disturbing motion. Current high-frequency force-balance test can provide results in a fraction of the time required for aeroelastic model tests but incorporate linear mode shapes for sway and a uniform mode shape for torsion. Force-balance tests also do not provide information on possible aeroelastic effects which may increase or decrease loading and response. Research is proposed on second generation high-frequency force-balances and associated instrumentation which would overcome the model shape inaccuracies by allowing modal forces to be determined for various mode shapes. Badic research is also proposed on the influence of building motion on modal forces. The Principal Investigator is well qualified to conduct the research. The research will lead to improved force balance for use by commercial wind tunnel testing laboratories. Use of the improved balances will allow more accurate prediction of wind-induced response for complex structures where torsion is an important consideration and where mode shapes are not linear. Better understanding of aeroelastic effects will provide valuable information on limits to the application and force balance test