摘要：Because of the closed geographic conditions and the effect of uncertain factors during a catastrophe in an underground coal mine, a high failure rate of the sensor nodes after a disaster is a common phenomenon. To ensure normal communications after a disaster, an impact cushioning device is designed to ensure survival of the sensor nodes during the disasters like the tunnel collapse, gas explosion, and so on. First, a model for the spring absorbing system is built; an analysis based on the model shows that the impact cushioning device can survive the free impact due to the extremely short impact time and the small displacement despite the large force from the instantaneous impact. Second, a collision model between the impact cushioning device and the rock is built; an analysis based on the model shows that both the circuit boards and the shell of the device can survive a tunnel collapse because the maximum stress values of the shell material and the circuit boards during the collision process are much less than their yield strength values. Finally, we use a triangular wave to simulate the shock wave used to test the collision model. An analysis of the test shows that the shell of the device and circuit boards are still safe and reliable under the effects of a gas explosion for the same reason that the maximum stress values of the shell material and the circuit boards in the gas explosion process are much lower than their yield strength values.
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