Chapter 1 - Stress

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Objectives Course objective:  To understand the axial, shear and bearing stresses associated with simple truss design and analysis. Learning objectives: Identify the Greek symbols associated with normal and shear stress. Draw (or recognize the correct) free-body diagrams of particles, trusses, and frames/machines. Draw free-body diagrams of broken components. Apply Newton's Laws in two-dimensions. Sum forces in one direction (1.17) or two directions (0.98). Sum moments about one axis (1.12). Convert to consistent units of length (in., ft, mm, m), force (lb, kip, N), and stress (psi, ksi, Msi, Pa, kPa, MPa). Calculate normal (1.25), shear (1.17), and bearing (1.00) stress values. Determine the appropriate area. Judge whether to use the gross or net cross-sectional area for pinned axial members. Judge whether to use a solid or hollow (pipe) area. Judge whether a pinned connection is under single (1.23) or double shear (1.20). Evaluate bonded joints between plates (rectangular area) (1.12) or pipes (circumferential area) (1.26). Evaluate punching shear (area around edge of slug) (0.77). Evaluate bearing stress between flat surfaces (contact area) or curved surfaces (pinned connections; plate thickness × pin diameter). Evaluate shear stress on keys (0.94). Apply Newton's Laws and calculate stress values. Sum forces in one direction and calculate normal stress (1.20). Sum forces in two directions and calculate normal stress (0.93). Sum moments about one axis and calculate normal stress (1.20). The values in orange represent quiz performance.  One represents average.  Values greater than one represent easier topics.  Values less than one represent harder topics.

Concepts  (21 minutes) 1. mechanics video notes 2. normal stress video notes 3. shear stress video notes 4. bearing stress video notes

Demos  (11 minutes) 1. double shear test video 2. shear fixture video 3. punching fixture video 4. dowel bearing test video 5. bearing failure video 6. post bearing test 1 video 7. post bearing test 2 video

Problems  (32 minutes) assigned 3e 2e 1e aids WP format normal stress   yes   01.001   01.001*   01.001 video solution TENU     --   01.002   01.002*   01.002 strategy solution TENU     --   --   01.003   01.003 strategy solution --     --   --   01.004   01.004 -- -- TENU B42     yes   01.003   01.005*   01.006 -- solution TENU     --   01.004   01.006*   01.005 -- -- --     yes   01.005   01.007   01.007 video solution TENU     yes   01.006    01.008*   01.008 strategy solution GO     --   01.007   01.009*   01.010 strategy solution --     yes   01.008   01.010*   01.009 video solution TENU       --   01.009   01.011   --   --   --   TENU       --   01.010   01.012   --   --   --   TENU       --   01.011   01.013   --   --   --   --       --   --   01.014   --   --   --   --       --   01.012   --   --   --   --   TENU     --   01.013   01.015   01.011 strategy solution --       --   01.014   --   --   --   --   TENU       --   01.015   --   --   --   --   --   shear stress   --   01.016   01.016   01.012 strategy solution TENU     --   --   01.017*   01.013 strategy solution --     yes   --   01.018*   01.014 video solution TENU B43     --   --   01.019*   01.015 video solution --     yes   --   01.020*   01.016 strategy solution TENU B44     --   --   01.021*   01.017 strategy solution --     yes   --   01.022*   01.018 video solution TENU B45       --   01.017   --   --   --   --   TENU       --   01.018   --   --   --   --   --       --   01.019   --   --   --   --   TENU     --   01.020   01.024   01.020 strategy solution --     yes   01.021   01.023*   01.019 video solution TENU       --   01.022   --   --   --   --   TENU       --   01.023   --   --   --   --   TENU       --   01.024   --   --   --   --   --       --   01.025   --   --   --   --   --       yes   01.026   --   --   --   --   GO       --   01.027   --   --   --   --   TENU     --   --   01.025*   01.021 strategy solution --     --   --   01.026   01.022 -- -- --   bearing stress   --   --   01.027   01.023 strategy solution --     --   01.028   01.028   01.024 strategy solution --     --   --   01.029   01.025 video solution --       --   01.029   --   --   --   --   --       yes   01.030   --   --   --   --   TENU       --   01.031   --   --   --   --   --       --   01.032   --   --   --   --   TENU       yes   01.033   --   --   --   --   GO   stress on inclined plane   --   01.034   01.030   01.026 -- -- TENU     --   01.035   01.031   01.027 -- solution TENU     --   01.036   01.032*   01.028 -- -- TENU     --   01.037   01.033*   01.029 -- -- --     yes   01.038   01.034   01.030 -- solution TENU or GO     --   01.039   01.035*   01.031 -- -- --     --   01.040   01.036   01.032 -- -- --     --   01.041   01.037   01.033 -- solution --     --   01.042   01.038   01.034 -- -- TENU     --   01.043   01.039*   01.035 -- -- --     --   01.044   01.040   01.036 -- -- TENU     --   01.045   01.041   01.037 -- solution --   * numbers changed between first and second editions props