SBIR Phase I: A Novel System for Uniform Preload in Bolted Joints

这项小型企业创新研究（SBIR）第一阶段项目的广泛影响是开发一种改进的螺栓紧固技术，适用于各种行业，包括可再生能源、发电、交通运输和基础设施。自19世纪引入现代紧固件以来，使用扭矩扳手的基本螺栓紧固方法基本保持不变。这导致多螺栓连接的预紧力变化高达30%。包括预载荷传感在内的新方法，虽然成本很高，但可以将这种变化降低到15%。高预载荷变化导致接头效率低下，螺栓松动，螺栓破裂，并在接头的使用寿命泄漏问题。提出的创新可能会将这种差异降低到5%，这是一个显著的改进。此外，与目前的四道紧固方法相比，它只需要两道即可紧固多个螺栓连接，节省了时间和劳动力。该技术的成功实施将有利于降低能源成本，特别是在美国快速增长的海上风电。此外，它将有助于防止核，石化，石油和天然气行业的接缝危险泄漏，防止交通，基础设施和重型机械行业的接缝振动松动。该技术将现有的广泛使用的扭矩扳手和超声波螺栓张力测量等技术与独特的专有计算机算法相结合。提出的创新提供了螺栓张紧的精确控制，这对多螺栓法兰连接的可靠性至关重要。基本概念已经通过高保真仿真得到了验证。在第一阶段的研究中，将继续对更现实的多螺栓连接进行模拟研究，以进一步验证该算法。第一阶段研究的主要目标是对所提出的算法进行实验验证和优化。在超声波预压传感器的帮助下，将在按比例缩小的法兰接头上进行广泛的测试。第二个目标是基于该系统开发最小可行产品概念。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact of this Small Business Innovation Research (SBIR) Phase I project is the development of an improved bolt tightening technology applicable to a wide variety of industries including renewable, power generation, transportation, and infrastructure. The basic bolt-tightening method utilizing a torque-wrench has remained largely unchanged since the introduction of the modern fastener in the 1800s. This results in a preload variation of up to 30% in a multi-bolt joint. New methods, including preload sensing, reduce this variation down to 15% albeit at a high cost. High preload variation leads to inefficient joints, bolt loosening, bolt rupture, and leakage problems over the joint’s lifetime. The proposed innovation can potentially reduce this variation down to 5%, a significant improvement. Additionally, it allows multi-bolt joint tightening in just two passes compared to the current method of four passes which saves time and labor. Successful implementation of the proposed technology will be beneficial in reducing the cost of energy, in particular, offshore wind which is poised for rapid growth in the US. Additionally, it will help prevent hazardous leakage of joints in the nuclear, petrochemical, and oil and gas industries and prevent vibration loosening of joints in the transportation, infrastructure, and heavy machinery industries.The proposed technology combines existing, widely used technologies, such as a torque-wrench and ultrasonic bolt tension measurement, with a unique and proprietary computer algorithm. The proposed innovation offers precise control of bolt tensioning, which is essential for the reliability of multi-bolt flange joints. The fundamental concept is already proven through high-fidelity simulations. In Phase I research, simulation studies will continue on more realistic multi-bolt joints to further validate the algorithm. The primary goal of Phase I research is the experimental validation and optimization of the proposed algorithm. Extensive testing will be conducted on a scaled-down flange joint with the help of ultrasonic preload sensors. The secondary goal is the development of a minimum viable product concept based on this system.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.