# FEA for Optimizing Design and Fabrication of Frame Structure of Elevating Work Platforms
## 2 Materials and Methods
### Finite Element Model Development  
A 3D model of the EWP frame was developed using SolidWorks version 2023 software based on a generic EWP design commonly used in industrial and agricultural applications. The telescopic arm was modeled as a continuous structure with variable geometry, rather than a strictly homogeneous cantilever beam, to reflect the realistic design that includes welds, reinforcements, and connections (Figure 2). This approach allows the analysis to capture local stress concentrations and deformation patterns more accurately than assuming a uniform cantilever model. The model was refined to include detailed representations of the main telescopic arms, base structure, hinge points, joints, reinforcements, and their support structures. Critical features, such as weld seams, bolt connections, and bracket attachments, were explicitly modeled to capture stress concentrations and ensure realistic load transfer between sections, which are known to be critical areas where potential failures can occur. This approach enables the analysis to identify and evaluate the most critical regions under operational conditions. Figure 1: Spaces for maneuvering a telescopic elevating work platform. Figure 2: 3D model FE of EWP frame. where the following is true:  
_mp_: 80 kg (mass of a person);  
_me_: 40 kg (minimum mass of tools and material);  
_n_: the number of people allowed on the work platform. The mass of each person is assumed to act as a point load on the working platform and on any extension of the platform at a horizontal distance of 0.1 m from the upper inside edge of the upper handrail. The distance between the point loads must be 0.5 m (Figure 3). The mass of the equipment is assumed to act as a uniformly distributed load over 25% of the working platform plane. If the resulting pressure exceeds 3 kN m\({}^{-2}\), the percentage of 25% can be increased to a value that gives a pressure of 3 kN m\({}^{-2}\) (Figure 4). All of these loads are assumed to be placed in the locations that result in the most severe outcomes. The analysis includes both vertical and horizontal loads at various angles, with particular focus on angles that maximize shear stresses in the telescopic arm, as per the expected operational scenarios during pruning tasks. 3. Wind Load:  
According to the UNI EN 280, all mobile elevating work platforms used outdoors are considered to be subjected to wind pressure of 100 N m\({}^{-2}\), equivalent to a wind speed of  
Figure 4: Mass tools and material position as per UNI EN 280. Figure 3: Mass person position as per UNI EN 280. 12.5 m s\({}^{-1}\) (Beaufort scale 6). Wind load was selected as a key boundary condition because it is a significant external factor affecting the stability and safety of EWPs, especially in agricultural applications, where platforms often operate in open and unpredictable environments. Wind load directly influences the lateral stability of the telescopic arm and was, therefore, prioritized for detailed analysis. Although other factors like ground inclination and operator motion can also influence stability, wind load is standardized and universally applicable under UNI EN 280, making it the most representative external factor for this study. Wind stresses are assumed to act horizontally in the center of the area of the mobile elevating work platform parts, people and equipment on the working platform and should be considered as dynamic stresses. Shape coefficients applied to areas exposed to wind:  
1. L, U, T, I section: 1.6;
2. Box sections: 1.4;
3. Large flat areas: 1.2;
4. Circular sections, based on size: 0.8/1.2;
5. People directly exposed: 1.0. The entire surface area of a person must be 0.7 m\({}^{2}\) (0.4 m average width, 1.75 m height), with the center of the area 1.0 m above the level of the working platform. The exposed area of a person standing on a working platform behind an unperforated section of fencing 1.1 m high shall be 0.35 m\({}^{2}\), with the center of the area 1.45 m above the plane of the working platform.