Design of test blanket module attachments under electromagnetic loads by using a dynamic amplification factor envelope

Abstract

European Test Blanket Modules (TBMs) are attached to radiation shields through mechanical joints. The structural integrity of the joints must be ensured under non-periodic dynamic loading caused by accidental electromagnetic events. This requires the transient dynamic analysis of the TBM-Joint-Shield under multiple loading scenarios. As temperatures and dynamic characteristics of the TBM-Joint-Shield system are updated under the course of the ITER project, the design process of the joints can become very time-consuming. This work presents a methodology based on a response spectrum to simplify the design process of the joint under electromagnetic loads. The mechanical system TBM-Joint-Shield was modeled as a single degree of freedom lumped spring-mass-dashpot system. The dynamic amplification was determined for a wide range of frequencies using the Finite Element Method. Eventually, a design envelope for each loading category was obtained, which can be readily used for determining the dynamic amplification factor of any potential new design of the TBM + Joint + Shield system. Results showed that HCLL undergoes higher loads than HCPB, resulting in a dynamic amplification factor which varies from 1.25 to 2.0 for a damping of 4%.