Which forces are easier to design internal or external?

Internal forces are generally easier to design for than external forces. This is because internal forces, such as tension and compression within a structure, can be analyzed through established principles of statics and material behavior. In contrast, external forces, such as wind, earthquakes, or dynamic loads, are more variable and unpredictable, requiring complex modeling and consideration of safety factors. Hence, designing for internal forces typically allows for more straightforward calculations and design processes.