ESICS

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 x-axis: 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 x-axis: 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 y-axis for all bracket types
    • The x-y 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. In-Plane Eccentric Shear Loads

Loads that are applied to the plane of the pattern are in-plane 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 in-plane eccentric loads.

1.2. Out-of-Plane Eccentric Axial Loads

Loads that are applied out of the plane of the bolt pattern are out-of-plane shear loads. This load passes through the centroid of the bolt pattern in the x-y plane however, its line of action is offset from the centroid in the z-direction.

As discussed above every wall mount bracket has a unique geometry therefore for a specific bracket type there could be out-of-plane or in-plane 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 Z-Force 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