caltester:caltesterplus:documentation:calculations
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
caltester:caltesterplus:documentation:calculations [2024/06/19 13:47] – created sgranger | caltester:caltesterplus:documentation:calculations [2024/09/06 13:53] (current) – [Calculations] wikisysop | ||
---|---|---|---|
Line 1: | Line 1: | ||
- | ====== | + | ====== |
+ | |||
+ | ===== Graphics | ||
The following graphics are from the [[https:// | The following graphics are from the [[https:// | ||
- | {{Fig1CalTesterArticle.png}} | + | {{:Fig1CalTesterArticle.png}} |
- | {{Fig2CalTesterArticle.png}} | + | {{:Fig2CalTesterArticle.png}} |
- | ====== Calculations | + | ===== Calculations ===== |
The following calculations and explanations are from the [[https:// | The following calculations and explanations are from the [[https:// | ||
Line 16: | Line 18: | ||
Free-body diagram of testing device: Fp, ground reaction force; Fg, gravitational force (weight); Fa, applied force; r, position vector between tips (p to a) of testing device rod:\\ | Free-body diagram of testing device: Fp, ground reaction force; Fg, gravitational force (weight); Fa, applied force; r, position vector between tips (p to a) of testing device rod:\\ | ||
- | {{Calc1CalTesterPlusArticle.png}}\\ | + | {{:Calc1CalTesterPlusArticle.png}}\\ |
Thus, r and A are parallel and the test device rod orientation (r) is defined entirely by the vector quantity A that is derived from FP measurements (Fp) and the physical characteristics of the testing device (Fg/2, i.e.the weight of the rod and its center of mass location; in this case, half the rod length).\\ | Thus, r and A are parallel and the test device rod orientation (r) is defined entirely by the vector quantity A that is derived from FP measurements (Fp) and the physical characteristics of the testing device (Fg/2, i.e.the weight of the rod and its center of mass location; in this case, half the rod length).\\ | ||
- | {{CalTesterPlus_DeltaTheta.jpg}}\\ | + | {{:CalTesterPlus_DeltaTheta.jpg}}\\ |
- | The rod orientation variable ( {{DeltaTheta.jpg}}) is determined from the dot product of the unit vector along A and the unit vector aligned with the long axis of the rod (r) as determined using the motion capture components.\\ | + | The rod orientation variable ( {{:DeltaTheta.jpg}}) is determined from the dot product of the unit vector along A and the unit vector aligned with the long axis of the rod (r) as determined using the motion capture components.\\ |
\\ | \\ | ||
**Section II : Equation for evaluating the static equilibrium assumption**\\ | **Section II : Equation for evaluating the static equilibrium assumption**\\ | ||
Line 27: | Line 29: | ||
Under 2D dynamic conditions, the following holds:\\ | Under 2D dynamic conditions, the following holds:\\ | ||
- | {{CalTesterPlus_Eq4_v2.jpg}}\\ | + | {{:CalTesterPlus_Eq4_v2.jpg}} \\ |
\\ | \\ | ||
Rewriting the left-hand side of Eq. (4)\\ | Rewriting the left-hand side of Eq. (4)\\ | ||
- | {{CalTesterPlus_Eq5_v2.jpg}}\\ | + | {{: |
\\ | \\ | ||
- | Rearranging Eq. (5), the magnitude of the angular displacement ( {{Beta.jpg}} ) between vectors r and A due exclusively to the inertial terms can be isolated:\\ | + | Rearranging Eq. (5), the magnitude of the angular displacement ( {{:Beta.jpg}} ) between vectors r and A due exclusively to the inertial terms can be isolated:\\ |
\\ | \\ | ||
- | {{CalTesterPlus_Eq6_v2.jpg}}\\ | + | {{:CalTesterPlus_Eq6_v2.jpg}} \\ |
\\ | \\ | ||
- | where r is the length of the testing device rod, Icg the moment of inertia of the test device rod about the center of mass location, m the mass of the testing device rod and {{ThetaDoubleDot.jpg}} is the angular acceleration of the testing device rod relative to an inertial reference frame. | + | where r is the length of the testing device rod, Icg the moment of inertia of the test device rod about the center of mass location, m the mass of the testing device rod and {{:ThetaDoubleDot.jpg}} is the angular acceleration of the testing device rod relative to an inertial reference frame. |
- | CalTesterPlus does not calculate {{Beta.jpg}} since it operates under the assumption that there is no angular acceleration. For this reason it is important to move the CalTester rod slowly at a constant speed. | + | CalTesterPlus does not calculate {{:Beta.jpg}} since it operates under the assumption that there is no angular acceleration. For this reason it is important to move the CalTester rod slowly at a constant speed. |
caltester/caltesterplus/documentation/calculations.1718804860.txt.gz · Last modified: 2024/06/19 13:47 by sgranger