How does the integration of advanced materials, such as composites and alloys, impact the design and performance of mechanical engineering systems? Specifically, how does the selection of materials influence factors like structural integrity, durability, and efficiency in various applications, from aerospace to automotive engineering? Moreover, what theoretical frameworks and methodologies are employed in analyzing the behavior of these materials under different operating conditions and loads? Exploring the theoretical foundations underlying material science and mechanical engineering practices could illuminate key insights into optimizing design processes and achieving superior performance and reliability in complex mechanical systems.