Which of the above is used in joining parts in aeroplanes and why?

 In modern aircraft manufacturing, welding is the primary method used for joining metal parts. Welding offers several advantages that make it well-suited for the aerospace industry, including the construction of airplanes. Here are some reasons why welding is commonly used in aircraft manufacturing:

1. Weight Considerations:

   • Welding allows for the creation of strong and lightweight joints. In the aerospace industry, minimizing weight is crucial for fuel efficiency and overall performance.

2. Structural Integrity:

   • Welded joints can provide high structural integrity, and the continuous nature of the weld can distribute loads more evenly, reducing stress concentrations.

3. Design Flexibility:

   • Welding allows for a variety of joint configurations and is versatile in joining different materials, including various alloys used in aerospace applications.

4. Efficiency and Speed:

   • Welding is often a faster process compared to traditional riveting. The efficiency of welding contributes to reducing production time and associated costs.

5. Automated Processes:

   • Modern aircraft manufacturing often involves automated welding processes, ensuring consistency and precision in the fabrication of joints.

6. Aerodynamics and Surface Smoothness:

   • Welded joints can contribute to a smoother surface finish, which is important for aerodynamics and fuel efficiency.

7. High-Strength Materials:

   • Welding is capable of joining high-strength materials commonly used in aerospace applications, such as aluminum and various alloys.

While welding is prevalent in aircraft manufacturing, it's worth noting that different joining methods, including riveting, may be employed for specific components or in certain situations. For example, some structural components, like the fuselage, may be welded, while others, like certain panels or access doors, may be riveted. The choice depends on factors such as the specific requirements of the part, the materials used, and the desired balance between weight, strength, and manufacturing efficiency. Overall, the aerospace industry employs a combination of advanced welding techniques and other joining methods to meet the stringent requirements of aircraft design and performance.