Eccentrically Loaded Bolt Group: ENHANCED COEFFICIENT CALCULATOR

When the province and the city of Cebu in the Philippines were respectively placed under Enhanced Community Quarantine (ECQ) on March 25, 2020 and March 28, 2020 to stop the spread of Corona Virus, I was virtually placed under house arrest together with the rest of the household members. People call it a lockdown. Freedom of movement was virtually curtailed as all residents of the province are placed under home quarantine at their residences in order to reduce the risk of exposure to and transmission of the COVID-19. To this end, no one is allowed to leave their residence except when purchasing food with Enhanced Community Quarantine Pass (ECQP) and other necessities. Government then pushed the work-from-home scheme to keep employees safer from COVID-19.

And while many are having a hard time adjusting to work-from-home scheme as a result of the coronavirus pandemic, I’ve been working from home already for a year now as structural steel connection designer for McLaren Engineering Group. Thanks God, to this day, the flow of projects coming from McLaren seems unaffected by the current situation in the US due to COVID-19. The US has been severely affected by the corona virus and has already surpassed Italy's infection cases as of this writing. Yet, Italy still holds the top spot in terms of the death toll -- that is if we are to believe Wuhan's doctored death statistics from COVID-19.

Being used to 'work-from-home' scheme, staying productive during the lockdown was never an issue to me. In less than two weeks since the declaration of the ECQ in Cebu City, I was able to write a program in javascript in addition to doing my usual job for McLaren Engineering Group. If the government has 'Enhanced Community Quarantine', I also have 'Eccentrically Loaded Bolt Group - Enhanced Coefficient Calculator'.

The program is an enhanced version of the same program previously posted here with the following updates and enhancements:

1. The program now accepts bolt group of any geometry by specifying bolt point x and y coordinates; may it be arranged symmetrically or arranged in staggered way.
2. The program generates a graphics layout of a bolt group with each bolt point labeled indicating its position on the generated table and its coordinates. The graphics also indicate the location of the center of gravity (CG).
3. Load vertical and horizontal eccentricities can now be specified. Both eccentricities are measured from the center of gravity (CG) of the bolt group. CG's coordinates are indicated on the graphics layout of the bolt group. Load is graphically represented by an arrow that rotates and moves in response to angle and eccentricity coordinates inputs respectively.
4. The program generates a mathematical solution to Instantaneous Center of Rotation showing the instantaneous center measured from CG and the equilibrium check. The presence of a VISUAL mathematical solution reinforces the idea that the solution itself is correct.

ECCENTRICALLY LOADED BOLT GROUP - ENHANCED COEFFICIENT CALCULATOR

BOLT GROUP LAYOUT:

Load Angle Ø from the Vertical [DEGREES]
Load x-Axis Eccentricity (measured from CG)
Load y-Axis Eccentricity (measured from CG)

ADD BOLT ENTRY:
Data Entry Mode
Bolt x-Coordinate
Bolt y-Coordinate
Bolt Entry Count

BOLT COORDINATES/BOLT FORCES:

***SOLUTION NOT FOUND***

(Unable to calculate the value of Bolt Group Coefficient C)

Please download the Excel Spreadsheet here and use/choose the SOLVER Version of the Spreadsheet to calculate the Bolt Group Coefficient C.

SOLUTION:

• BOLT GROUP COEFFICIENTS: C = 0.00 C' = 0.00 • BOLT GROUP CENTER OF GRAVITY (CG): x = CG Distance along X-axis = 0'-0" y = CG Distance along Y-axis = 0'-0" • BOLT GROUP INSTANTANEOUS CENTER (IC): (Measured from CG) xLo = IC Distance along X-axis = 0'-0" yLo = IC Distance along Y-axis = 0'-0" • EQUILIBRIUM CHECK: ΣM = Bolt Group Moment Resistance = 0.000 Kip-in ΣRx = Bolt Group Resistance along the Horizontal = 0.000 Kips ΣRy = Bolt Group Resistance along the Vertical = 0.000 Kips ro = Perpendicular Distance from IC to Load Line = 0'-0" `P + sumM//r_o` = 0.00 `larr`(Static Equilibrium Eq-1) P = -`sumM//r_o` = 0.000 Kips Px = X-Component of force P = P sin Ø = 0.000 Kips Py = Y-Component of force P = P cos Ø = 0.000 Kips `P_x` + `sumR_x` = 0.000 `larr`(Static Equilibrium Eq-2) `P_y` + `sumR_y` = 0.000 `larr`(Static Equilibrium Eq-3) • NOTATIONS/FORMULAS: R = Rult(1 - e-10Δ)0.55 Rult = 74 Kips (based on ¾"Ø ASTM A325 Bolt) Δmax = 0.34 Kips (based on ¾"Ø ASTM A325 Bolt) Δi = Δmax(rLi/rLmax) rLi = `sqrt(yL_i^2 + xL_i^2)` Ri = Rult(1 - e-10Δi)0.55 Rx = `R_i*yL_i//rL_i` Ry = `R_i*xL_i//rL_i` M = `R_i*rL_i` C = P / Rult C' = Σ[Li (1 - e-(10 Li Δmax / Lmax))0.55]

Notes:

1. To add bolt data/entry, set 'Data Entry Mode' to 'ADD BOLT ENTRY'. Specify 'Bolt x-Coordinate' and 'Bolt y-Coordinate' then click on the 'Apply Entry' button.
2. To delete bolt data/entry, click on the table the data you want deleted then click on the 'Delete Entry' button.
3. To clear all the bolt data/entries on the table, click on the 'Delete Entries' button. An alert dialog will pop-up asking you to confirm the action. Click on the 'OK' button to confirm or the 'CANCEL' button to cancel the action.
4. To edit bolt data/entry, set 'Data Entry Mode' to 'EDIT BOLT ENTRY'. Click on the table the data you want to edit. Edit 'Bolt x-Coordinate' and/or 'Bolt y-Coordinate' then click on the 'Apply Entry' button.
5. Specify 'Load Angle Ø from the Vertical', 'Load x-Axis Eccentricity', and 'Load y-Axis Eccentricity'. Click on the 'SOLVE' button to calculate.
6. Click on the 'Sample' button to create a sample bolt data/entries.
7. The functions of the rest of the buttons are self-explanatory. Just feel free to explore...
8. Input for bolt coordinates and load eccentricities can be accomplished in several ways. Input can be either in decimal or imperial/architectural format. If you enter, for example, 144.5 or 144.5", the number is automatically converted to 1'- 1/2". If you enter 144.5', the number is converted to 144'-6". A number without a trailing apostrophe or quotation mark is read in inches.
   You may also enter a number in imperial (FIS) format containing fraction and decimal. For example, if you enter 1.5'-1 1/2", the number is converted to 1'-7 1/2". If you enter 1.5'-1.5", the number is also converted to 1'-7 1/2".
   Unrecognized input format, however, is automatically interpreted and converted to ZERO.