Poster: Vi-Detect: Fine-Grained Vibration-Based Component Looseness Detection Using Smartphones

Many civil structures are at risk of failure due to bolts loosening under shock or vibration. Early detection of looseness is critical for safety. In this research, we utilize mathematical model with motion equations and optimization technique to estimate parameters that can detect looseness. A novel tightness index is introduced to quantify the extent/degree of looseness. The method was validated on wood and steel structures for demonstrating its effectiveness.