The ability to predict spatial elements based on two-dimensional figures, evaluate engineering elements, identify expected deformations, and predict possible failure mechanisms are critical for engineers. However, in applied mechanics courses, many undergraduate engineering students struggle with applying these skills to engineering problems. Previous studies have shown that three-dimensional (3D) visualization can help students to improve spatial understanding, learn material more permanently, and improve their creativity. Building on this phenomenon, interactive 3D models using Augmented Reality (AR) were incorporated in a Mechanics of Materials course. This course is an entry-level course and major requirement for different engineering disciplines including Civil, Mechanical, Biomedical, Materials Science, and Manufacturing Engineering. To evaluate the effectiveness of 3D models in students' performance, an independent study was conducted with students in the course. In the study, one group only had access to a traditional, two-dimensional (2D) schematic, while the other group had access to a 3D model. The experimental and control groups were then swapped for the second problem. The results of this study revealed that 3D models significantly improve student performance. This paper reviews the design and results from the study, with the expectation that showing the impact on students' performance will help institutions add similar activities to their engineering courses to improve students learning.