# Augmented Reality Visualization of Modal Analysis Using the Finite Element Method
## 1 Introduction  
Finite Element Analysis (FEA) is commonly used in industrial design and is highly preferred by engineers. By using FEA, engineers understand the behavior of the part under different forces and constraints. Design process has two important steps: the drawing and the analysis of designed elements. Under the design classification, functional and aesthetical aspects are mainly taken into account. In the analysis classification, what is taken into consideration is the fact that the designed product provides the desired resistance under real working conditions. However, whether the completed design will fulfill the desired task when the operating conditions are implemented is unclear. Necessary engineering calculations and analyses must be performed in advance to respond to such issues. This is aimed at minimizing risks by predicting the real-life working conditions of the designed product or system through analysis. With a finite element analysis, the part can be made resistant to the loads to which it is exposed, and unnecessary material use is also prevented. Given the various benefits brought by this type of analysis, it is critically important to conduct the analysis before the beginning of the production process. With FEA, the testing of complex products can be carried out in a virtual environment without actual production. As a result, there is no need to produce the parts for testing purposes. This process reducesthe need for prototyping and functionality tests that are difficult to implement. This minimizes the material and labor costs. Subsequently, tests can be continued on the first series of prototypes. Featuring easy boundary conditions, FEA facilitates the use of the right material by achieving optimum results in designs and saves time by shortening the design process. FEA is also known as one of the most effective and common methods for addressing ranges of different issues in engineering and physics [1]. This method is based on the modeling of complex structures with smaller structures that can be calculated. This method is also used in almost all fields of engineering, including structural analysis (e.g., static, dynamic, linear and nonlinear), heat transfer, and flow analysis. FEA is the first step for the optimization of the products. FEA is used to identify the weaknesses and strengths of designs. While FEA enables engineers to apply and test a scenario in a virtual environment, by now this virtual environment has been provided by computer simulations. With the development of technology, it is predicted that engineering analysis will be supported with Augmented Reality (AR) and Virtual Reality (VR). Accordingly, this study aimed to combine both FEA and AR. AR offers the opportunity to support people with additional information while they are performing their role. Finite element analysis helps to anticipate product real behavior under real effects such as vibration, forces, heat and flow. FEA uses a large number of finite elements to divide real objects. Each element's behavior is calculated via mathematical equations. All elements' behaviors are collected by computer to predict the real objects' behaviors. Augmented reality uses the object recognition features of the devices to visualize virtual objects on real images (Figure 1a). AR overlays digital content onto a live view of the real environment, is normally implemented on a wearable AR headset or smartphone/tablet device, and has been used in a number of applications [2; 3; 4]. By using the AR-FEA system, engineers can perform and evaluate simulations in a real environment. Simulation results can be visualized on real components. AR-FEA visualization allows for the easy identification of critical areas and a better interpretation of data. Displaying the analysis result in a real environment strengthens FEA. In the literature, many modal analysis studies have been conducted with finite element analysis. The results of the modal analysis were always viewed on the computer.