ESICS: MAFI Wall Mount Bolt Force Calculations
General Overview
In this section, you will address the following items:
 Brief introduction  What does it calculate? Why?
 In this section, we will identify the method used for the calculations of forces on wall mount bolts
 Each wall mount bracket has a specific geometry therefore different set of equations where used for each bracket
 Main outputs
 The main output of these calculators are the maximum shear and axial forces on the bolts.
 Main limitations  e.g. maximum quantity of equipment allowed, countries supported etc
 Note that this calculator does not perform bolt capacity calculations
 These bolt calculations are specific to MAFI Brackets and geometry and Cannot be used for any other type of bracket
 Basic assumptions
 Load Case Assumptions:
 Load Case 1: Loads perpendicular to wall + Weight of Equipment (Antenna, RRU, Dishes, Poles, Brackets...)
 Load Case 2: Loads parallel to wall + Weight of Equipment
 Geometry Assumptions:
 Wall mount brackets and a portion of the mounted pole are considered a frame system
 The frame support conditions are based on the following
 Fixed about the xaxis: If the bolt pattern has 2 rows of bolts  Heavy Duty Wall Mount  MAFI 2414  Remedial Wall Bracket  MAFI 2415  Large Offset Wall Mount  MAFI 3544
 Pinned about the xaxis: If the bolt pattern has 1 row of bolts
 Medium Duty Wall Mount  MAFI 3541

 Corner Wall Mount Minimal Offset  MAFI 49692
 Fixed about the yaxis for all bracket types
 The xy plane is the face of the bolt pattern
 Load Path Assumptions:
 Loads from the mounted pole solver will be used for the frame system inputs
 The absolute max reactions from the portal frame are used for the bolt calculations
 This will be extensively explained in another article
Analysis Method
The purpose of this section is to calculate the maximum axial and shear force on an individual in the specified bolt pattern. Note that the number of bolts and the arrangement of bolts is dependent on the selected Wall mount Bracket.
1. Bolt Pattern Force Distribution
When calculating the loads for an individual bolt in a bolt pattern it is important to understand the distribution of applied loads amongst every bolt. Therefore identifying the shear and axial loads on the bolt pattern is the first step in calculating the bolt loads.
After identifying the applied shear and axial loads they are translated to the centroid of the pattern. The forces and moments at the centroid are then converted into axial and shear forces acting at the individual bolt.
Every individual wall mount has a unique bolt pattern and loading geometry. Therefore two different loading conditions are considered in the calculation of bolt loads for every individual wall mount.
1.1. InPlane Eccentric Shear Loads
Loads that are applied to the plane of the pattern are inplane eccentric shear loads. This load is considered eccentric since it does not act on the centroid of the bolt pattern. The following wall mount brackets have inplane eccentric loads.
1.2. OutofPlane Eccentric Axial Loads
Loads that are applied out of the plane of the bolt pattern are outofplane shear loads. This load passes through the centroid of the bolt pattern in the xy plane however, its line of action is offset from the centroid in the zdirection.
As discussed above every wall mount bracket has a unique geometry therefore for a specific bracket type there could be outofplane or inplane loading. Tabel below demonstrated the loading conditions of each wall mount bracket. Note that the location where the mounted pole is installed determines the location of the reaction on the brackets. Therefore if the pole is eccentric from the center of the bracket then the loading will be eccentrically applied to the bolts. This is further explained in the Reaction Calculations article.
2. Shear and Axial Loads Calculated from Loads Perpendicular to the Wall
In this section, the axial loads on the bolts have been calculated for loads case 1: Loads perpendicular to wall + Weight of Equipment.
2.1. Shear Loads on Bolts for Medium Duty Wall Mount  MAFI 3451
Note that the Shear loads for MAFI Remedial Wall Mount Bracket  MAFI 2415 and Large Offset Wall Mount  MAFI 3544 are calculated using the same method.
2.2. Shear Loads on Bolts for Heavy Duty Wall Mount MAFI 2414
2.3. Shear Loads on Bolts for Corner Wall Mount  Minimal Offset  MAFI 43692
2.4. Axial Loads on Bolts for Medium Duty Wall Mount  MAFI 3451
2.5. Axial Loads on Bolts for Heavy Duty Wall Mount MAFI 2414
Note that the axial load for MAFI Remedial Wall Mount Bracket  MAFI 2415 and Large Offset Wall Mount  MAFI 3544 are calculated using the same method however they do not have ZForce on Bolts Due to My. about Centroid. Pz,My,PR since the Mounted pole is inline with the centroid of the bolt pattern.
2.6. Axial Loads on Bolts for Corner Wall Mount  Minimal Offset  MAFI 43692
3. Shear and Axial Loads Calculated from Loads Parallel to the Wall
3.1. Shear Loads on Bolts for Medium Duty Wall Mount  MAFI 3451
Note that the Shear loads for MAFI Remedial Wall Mount Bracket  MAFI 2415 and Large Offset Wall Mount  MAFI 3544 are calculated using the same method.
3.2. Shear Loads on Bolts for Heavy Duty Wall Mount MAFI 2414
3.3. Shear Loads on Bolts for Corner Wall Mount  Minimal Offset  MAFI 43692
3.4. Axial Loads on Bolts for Medium Duty Wall Mount  MAFI 3451
3.5. Axial Loads on Bolts for Heavy Duty Wall Mount MAFI 2414
Note that the axial load for MAFI Remedial Wall Mount Bracket  MAFI 2415 and Large Offset Wall Mount  MAFI 3544 are calculated using the same method.
3.6. Axial Loads on Bolts for Corner Wall Mount  Minimal Offset  MAFI 43692