SHMS FEA Review Prepared for: Jefferson Lab Prepared by: AMSEC LLC

Introduction AMSEC LLC optimized the Jefferson Lab SHMS carriage design and performed a finite element analysis (FEA) Per ANSI/AISC , the following stress criteria apply: – Bending Stress Allowable, σ b = 0.6*σ y For ASTM A36 Steel, σ y = 36 ksi, σ b = 21.6 ksi For ASTM A572 Steel, σ y = 50 ksi, σ b = 30 ksi – Shear Stress Allowable, τ b = 0.4*σ y For ASTM A36 Steel, σ y = 36 ksi, τ b = 14.4 ksi For ASTM A572 Steel, σ y = 50 ksi, τ b = 20 ksi Overstresses found will be examined with the following criteria: – Insure the overstress is a localized (peak) stress – Check to verify stress are below material yield strengths For ASTM A36 Steel, σ y = 36 ksi, τ y = 0.5*σ y = 18 ksi For ASTM A572 Steel, σ y = 50 ksi, τ y = 0.5*σ y = 25 ksi Per Jefferson Lab, the following buckling criteria apply: – Minimum Factor of Safety on Buckling = 1.4 – Criteria applies only to buckling modes exhibiting downward gravity

Full Model Front pivot housing is constructed with ASTM A572 Steel The majority of the carriage structure is constructed with ASTM A36 Steel

Full Model – Maximum Von Mises Stress Scale is set to show elements above allowable in red Overstress areas are localized and are examined further on following slides

Criteria Plot – Elements Above Allowable Bending Stress Scale is set to show maximum stress Maximum Von Mises Stress = 35.5 ksi, including both A36 and A572 Steel material Front pivot housing is constructed with ASTM A572 Steel

Full Model – Maximum Shear Stress Scale is set to show elements above allowable in red Overstress areas are localized and are examined further on following slides

Criteria Plot – Elements Above Allowable Shear Stress Scale is set to show maximum stress Maximum Shear Stress = 17.4 ksi, including both A36 and A572 Steel material Front pivot housing is constructed with ASTM A572 Steel

Full Model – First Buckling Mode

Conclusion Weight of the SHMS carriage structure is approximately 103 tons, excluding concrete The Maximum Von Mises Stress was 35.5 ksi – This was a peak stress, and was still found to be below yield The Maximum Shear Stress was 17.4 ksi – This was a peak stress, and was still found to be below yield The first buckling mode had a factor of safety of 1.4 – This accounts for the first real buckling mode