Chapter 15 - Combined Loads

Announcements If you have two final exams scheduled for the same time period or three final exams on the same day, you must visit the Registrar's office as soon as possible. You will be given a letter to deliver to the instructor that is to reschedule your final.  It is not determined by your instructors.

Objectives Course objective:  To use the mechanics of materials technique to analyze a few structures. Learning objectives: Apply concepts from chapters 1-14 to structures with combined axial and torsion loads. single torque (1.47) multiple torques (1.43) Apply concepts from chapters 1-14 to structures with combined shear-forces and bending-moments. V&M given (1.00) find V&M and then stresses (0.93) Apply concepts from chapters 1-14 to structures with combined axial, torsion, shear-force, bending-moment, and pressure loads. rectangular posts (0.80) cylindrical posts (0.90) pressurized pipes (0.51) The following steps are required in the topics above. Recognize where stresses do/do not occur for each load type. Recognize where the largest stresses occur for each load type. Recognize the stress direction associated with each load type. Recognize when an axis has no normal stress. Draw properly oriented and labeled stress elements. 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  (12 minutes) 1. combined loadings video notes 2. semester summary & saint venant's principle video notes 3. message from former ide 110 student notes

Demos  (9 minutes) 1. liebherr demonstration video 2. turbo entabulator  :) video

Quiz Prep 1.  As you have seen in the homework, many of the chapter 15 questions ask for the normal stress in the x and y (or z) directions and the shear stress at point H (or K).  On the quiz, these three numbers will often be three separate questions. 2.  One of the normal stresses at H and K is usually zero, but please be careful selecting zero as an answer.  It will be worth as much as the non-zero answers.  That way you cannot identify which answers are zero simply by looking at the point values.  One might also consider the zero answers as "free" points if you can quickly identify the zero locations by looking at the structure and its loadings. 3.  The centroid and moment of inertia values for I and tee shapes are often provided in the quiz questions, but you will probably need to calculate these values for rectangles and circles. 4.  You will have to calculate principals and/or max shear for few, if any, of the problems.

Problems  (135 minutes) assigned 3e 2e 1e aids WP format   axial + torsion       15.001*   15.001   15.001 -- -- --     yes   15.002+   15.002   15.002 video solution TENU         --   15.003   15.003 -- -- --         --   15.004   15.004 strategy solution TENU B103         15.003   --   --   --   --   TENU       yes   15.004   --   --   --   --   GO           15.005*   15.005   15.005 -- -- TENU     yes   15.006   15.006   15.006 strategy solution TENU         15.007*   15.007   15.007 -- -- --     yes   15.008   15.008   15.008 video solution TENU         15.009   15.009   15.009 -- -- --         15.010   15.010*   15.010 strategy solution TENU         --   --   15.011 -- -- --         --   --   15.012 -- -- --     yes   15.011/12   15.011/12   15.013 video solution TENU/--         15.013/14   15.013/14   15.014 strategy solution TENU/TENU         15.015*   15.015   15.015 -- -- TENU     yes   15.016*   15.016   15.016 strategy solution GO         --   15.017   15.017 -- -- GO B107         15.017   --   --   --   --   GO           --   15.018   15.018 strategy solution --         15.018   --   --   --   --   --     beams       --   --   15.019 -- -- --     yes   15.019*   15.019   15.020 video solution   GO       yes   15.020*   15.020   15.021 strategy solution GO         --   --   15.022 strategy solution   --           --   --   15.023 strategy solution   --           --   --   15.024 video solution   --           15.021/22*   15.021/22   15.025 -- -- TENU/--         15.023/24*   15.023/24   15.026 strategy solution --/TENU         --   --   15.027 strategy solution --     yes   15.025/26*   15.025/26   15.028 video solution TENU/TENU         15.027   15.027   15.029   -- -- --         15.028   15.028   15.030 video solution   GO           15.029   15.029   15.031 -- --   TENU           15.030   15.030   15.032 strategy solution --         --   15.031   15.033   --   -- --     yes   15.031   --   --   -- --   GO           --   --   15.034   --   --   --           15.032   15.032   15.035 -- -- TENU     yes   15.033   15.033   15.036 -- -- TENU   rectangular posts       --   15.034*   15.037 -- -- TENU B104         15.034   --   --   --   --   TENU           --   15.035*   15.038 strategy solution --         15.035   --   --   --   --   --       yes   15.036+   15.036   15.039 video solution TENU         15.037   15.037   15.040 strategy solution   --       yes   15.038   15.038   15.041 video solution GO         --   15.039/40   15.042 -- -- TENU B/GO B108   circular posts       --   15.041   15.043 strategy solution --         --   15.042   15.044 -- solution --         15.041   --   --   -- --   GO           15.042   --   --   -- --   TENU           15.043   15.043   15.045 -- --   --           15.044   15.044   15.046 strategy solution --     no/yes   15.045/46   15.045/46   15.047 video solution --/TENU     yes/no   15.047/48   15.047/48   15.048 -- -- GO/--         --   15.049/50   15.049 video solution --/--         15.049   --   --   -- --   TENU           15.050   --   --   -- --   TENU           15.051+   15.051   15.050 -- solution TENU         --   15.052   15.051 strategy solution TENU B105         15.052   --   --   -- --   TENU           15.053/54   15.053/54   15.052 -- -- GO/TENU   shafts       15.055   15.055   15.053 -- -- TENU         15.056   15.056   15.054 -- solution --         15.057/58   15.057/58   15.055 -- solution --/TENU   pipes       15.059+   15.059   15.056 strategy solution --         --   15.060   15.057 -- -- TENU B106         --   15.061   15.058 -- solution TENU B93         15.060   --   --   -- --   TENU           15.061   --   --   -- --   GO           15.062/63   15.062/63   15.059 -- -- TENU/--         15.064/65   15.064/65   15.060 -- -- GO/TENU         15.066/67   15.066/67   15.061 -- -- TENU/--   failure theories       15.068*   15.068   15.062 -- solution TENU         15.069*   15.069   15.063 -- -- --         15.070   15.070   15.064 -- solution TENU         15.071   15.071   15.065 -- -- TENU         15.072   15.072   15.066 -- -- --         15.073   15.073   15.067 -- -- --         15.074*   15.074   15.068 -- -- GO         15.075   15.075   15.069 -- -- --     yes   15.076   15.076   15.070 -- solution TENU         15.077   15.077   15.071 -- -- --         15.078   15.078   15.072 -- -- TENU         15.079   15.079   15.073 -- -- GO         15.080*   15.080   15.074 -- solution --         15.081*   15.081   15.075 -- -- --         15.082   15.082   15.076 -- solution --         15.083   15.083   15.077 -- -- TENU         15.084   15.084   15.078 -- solution TENU         15.085   15.085   15.079 --   --   --   * numbers changed between editions + problem statement changed between second and third editions props