4. Analysis (1) From Table 1, it is now necessary to subtract the recorded strains for zero force from the values recorded for the non-zero forces, so for example if strain gauge 5 reads -173 for F = 0 N and -152 for F = -100N, then the new strain for F =- 100N becomes-152-(-173) = 21 and similarly for the other force values and strain gauges. A new table may now be drawn up in which all strains are zero when F = 0 N. (2) The forces in each strut may now be determined from the strain gauge readings given the following data: Strut Diameter = 5.98 mm - Youngs' modulus for steel = 210 GPa The relevant equation will be: F = AE (1) where A is the strut cross-sectional area, & is a measured strain (use the adjusted values where zero force now corresponds to zero strain. (Remember to convert from microstrain to strain). 7 D 5 Ti 15 T F Fig. 7 Calculating Forces in Struts (3) The forces in the struts may also be calculated from statics using Equations (2) below: where in Fig. 7, = 45 T = Fseco T = -Ftane (2) Note that these Equations only apply when = 45 when the horizontal and vertical structs have the same length. Questions 1 to 10 require you to enter your strain gauge readings. Q1. Q2. Q3. Q4. Q5. Q6. Q7. Q8. Q9. For the applied load of -100N give your strain measurement in microstrains for strain gauge 5, having first subtracted the reading obtained for zero force. For the applied load of -200N give your strain measurement in microstrains for strain gauge 5, having first subtracted the reading obtained for zero force. For the applied load of -300N give your strain measurement in microstrains for strain gauge 5, having first subtracted the reading obtained for zero force. For the applied load of -400N give your strain measurement in microstrains for strain gauge 5, having first subtracted the reading obtained for zero force. For the applied load of -500N give your strain measurement in microstrains for strain gauge 5, having first subtracted the reading obtained for zero force. For the applied load of -100N give your strain measurement in microstrains for strain gauge 15, having first subtracted the reading obtained for zero force. For the applied load of -200N give your strain measurement in microstrains for strain gauge 15, having first subtracted the reading obtained for zero force. For the applied load of -300N give your strain measurement in microstrains for strain gauge 15, having first subtracted the reading obtained for zero force. For the applied load of -400N give your strain measurement in microstrains for strain gauge 15, having first subtracted the reading obtained for zero force. Q10. For the applied load of -500N give your strain measurement in microstrains for strain gauge 15, having first subtracted the reading obtained for zero force. Questions 11 to 20 require you to estimate the forces T1 and T2 using the strain gauge values from Questions 1 to 10 for the force Fapplied. Q11. For the applied load of -100N, using your results and Equation (1) in the briefing. estimate the force Ti Q12. For the applied load of -200N, using your results and Equation (1) in the briefing, estimate the force T Q13. For the applied load of -300N, using your results and Equation (1) in the briefing, estimate the force Ti Q14. For the applied load of -400N, using your results and Equation (1) in the briefing, estimate the force Ti Q15. For the applied load of -500N, using your results and Equation (1) in the briefing, estimate the force Ti Q16. For the applied load of -100N, using your results and Equation (1) in the briefing, estimate the force T2 Q17. For the applied load of -200N, using your results and Equation (1) in the briefing, estimate the force T2 Q18. For the applied load of -300N, using your results and Equation (1) in the briefing, estimate the force T Q19. For the applied load of -400N, using your results and Equation (1) in the briefing, estimate the force T Q20. For the applied load of -500N, using your results and Equation (1) in the briefing, estimate the force T Questions 21 to 30 require you to estimate the forces T1 and T2 theoretically. Q21. For the applied load of -100N, use Equation (2) in the briefing to estimate the force T1. Q22. For the applied load of -200N, use Equation (2) in the briefing to estimate the force T. Q23. For the applied load of -300N, use Equation (2) in the briefing to estimate the force T. Q24. For the applied load of -400N, use Equation (2) in the briefing to estimate the force T. Q25. For the applied load of -500N, use Equation (2) in the briefing to estimate the force T. Q26. For the applied load of -100N, use Equation (2) in the briefing to estimate the force T2. Q27. For the applied load of -200N, use Equation (2) in the briefing to estimate the force T. Q28. For the applied load of -300N, use Equation (2) in the briefing to estimate the force T2. Q29. For the applied load of -400N, use Equation (2) in the briefing to estimate the force T2. Q30. For the applied load of -500N, use Equation (2) in the briefing to estimate the force T. Table 1 Raw Results Force F (N) Strain Gauge 5 Strain Gauge 7 0 -176 S Strain Gauge 15 -003 -100 -176 IS -002 -200 -158 16 -027 -300 -141 16 -400 -125 16 -051 -075 -500 -106 17 -101