Design strength is achieved by multiplying which two factors?

Design strength is determined by taking the nominal strength of a material or structural element and multiplying it by the strength reduction factor. The nominal strength represents the theoretical maximum capacity of the material based on its properties and geometric configuration, while the strength reduction factor accounts for uncertainties in the material properties, construction practices, and the effects of loads. This combination reflects a more realistic design approach that ensures safety and reliability in engineering practice.

Using these two factors together helps engineers design structures that consider both the material's capabilities and the inherent uncertainties in the real-world application, ultimately leading to safer and more effective designs. In contrast, the other options do not accurately represent the relationship between strength and the factors involved in determining design strength.