Design flowchart

Notes

1. As an approximate rule, reinforced concrete elements designed for protection category 1 (θ < 2°) will exhibit a type 1 section and are likely to respond within the dynamic regime, whereas those designed for protection category 2 (θ > 2°) will exhibit a type 2 section and are likely to respond within the impulsive regime. However, this is not a hard-and-fast rule and the response time of the element (t_m) must always be calculated and compared with the duration of the load (t_d) to check that the correct response regime has been assumed in design.

2. For the unusual case of protection category 2 and response within the dynamic regime, a type 2 section should be assumed at this stage.