Measurement of dynamic battery pack properties

摘要

An example method includes positioning a mass at a height opposite a modulator characterized by a particular strain rate and support by a carrier moveably disposed opposite the mass. The method also includes releasing the mass such that the mass impacts the modulator, and an additional component connected to the carrier causes failure of a sample of material. The method further includes determining a displacement of the carrier corresponding to failure of the sample, determining a force applied to the modulator by the mass and resulting in failure of the sample, and determining at least one of a dynamic strength of the sample and a dynamic modulus of the sample. In such a method, the dynamic strength is based on the force applied to the modulator and the strain rate. Additionally, the dynamic modulus is based on the displacement of the carrier and the strain rate.

主权项

1. A method, comprising:
positioning a battery pack within an internal space of a test enclosure, the battery pack including an outer casing; positioning a tip of a plunger proximate to a top surface of the outer casing, wherein the plunger extends from within the internal space to a location external to the test enclosure and is moveable relative to the test enclosure in a first direction toward the battery pack; causing a first impact between a mass disposed opposite to the plunger and a piece of material having a known strain rate coupled to the plunger, the piece of material being disposed external to the test enclosure, wherein:
the mass is moveable in the first direction along a guide of a first frame,the first impact causes the plunger to move in the first direction, andcontact between the plunger and the outer casing punctures the casing at a failure point of the outer casing; determining a displacement of the plunger, caused by the first impact, at the failure point of the outer casing; determining a force applied to the piece of material, by the mass, at the failure point of the outer casing; and determining a dynamic strength (σ(ε) of the outer casing or a dynamic modulus (M(ε) of the outer casing, wherein the dynamic strength is determined as a function of the strain rate and the force applied to the piece of material and the dynamic modulus is determined as a function of the strain rate and the displacement of the plunger.