Session 1B-1 Introduction to Fatigue and Fracture of Steel Bridges 1 Advanced Technology for Large Structural Systems Center Lehigh University Fatigue and Fracture Design of Steel Bridges 钢桥的疲劳与断裂设计 Session 1B- -1 Introduction to Fatigue and Fracture of Steel Bridges 钢桥疲劳与断裂简介 Advanced Technology for Large Structural Systems Center Lehigh University Fatigue 疲劳 Progressive, localized, and perman