Method for measuring shrinkage stress in thermosetting polyurethane processing

The invention relates to the technical field of detection and evaluation of thermosetting polyurethane structural parts, and discloses a method for measuring shrinkage stress in thermosetting polyurethane processing, which comprises the following steps of: firstly, determining a temperature range in a measurement process according to a processing technology requirement; then the device is assembled, the device comprises two clamping plates, an insert, a pouring mold cavity, an axial force sensor, two temperature sensors and a connecting screw rod, and a pouring opening is formed in the side face of the pouring mold cavity; clearing the axial force sensor at room temperature, and starting to collect force and time; the zero position of the force sensor can be calibrated by collecting the readings of the force sensor at different temperatures in a non-loading state, so that the temperature effect error of the sensor caused by the processing temperature is reduced; the change of the shrinkage stress along with t