Method for calculating impact overpressure generated by explosion of cable joint

The invention discloses a method for calculating impact overpressure generated by explosion of a cable joint, which comprises the following steps of: 1, establishing a simulation model of a cable single-phase earth fault containing an electric arc, and solving a power value of a fault short-circuit electric arc on the simulation model; 2, establishing a temperature field-fluid field-solid field multi-physical field coupling model of the intermediate joint of the corresponding size of the cable, and taking the obtained power value of the fault short circuit arc as an input source of an equivalent heat source; and 3, solving temperature distribution, flow velocity distribution and pressure distribution in the temperature field-fluid field-solid field multi-physics field coupling model to obtain a pressure difference between the inside and the outside of the joint metal protective shell, which is impact overpressure generated by joint explosion. According to the method, a basis can be provided for development of