5.11 Using the Break Tool The Break tool features two methods for identifying a material break: %Drop and Rate. Break testing identifies when the material fractures or ruptures and provides a curve that can be used to identify the maximum load or distance prior to the break event. Both forms for break identification may be used in either tensile or compressive directions. 5.11.1 Drop % Algorithm The Drop % algorithm is the more commonly used method for deter- mining a sample break. This method first looks for the maximum stress or load. Once the maximum load is determined, the algorithm next looks for a % drop in load. So, if the maximum load was measured as 100N, and the load dropped to 80N, that is a 20% drop in load. The % Drop method is used in the L3 test setup steps for both tensile and compressive limits. This terminates or completes a test run when the maximum load is measured and the load drops be the specified percent value.
5.11.1.1 Drop % The Drop % is the value that the load decreases AFTER achieving its maximum value. The maximum value must first be met, then the algo- rithm will evaluate the data after the maximum value and will identify the point where the reduction in load equals the Drop %.
NOTE The Drop % is the percentage reduction in load AFTER first achieving its maximum load or distance value.
5.11.1.2 Drop % Algorithm Scope The scope for the Drop % algorithm is based on two specific points that defined the end points of a data segment. The scope segment is normally after the maximum load value that was measured and prior to where the load or distance returned to zero.
You may position the scope handles along either the y-axis or x-axis to define the data segment where you are interested in analyzing.
Or, you may implicitly specify your start and end scope points using values or other coefficients that can be used as anchors. Anchored coefficients display in yellow. It is common to determine the maximum load and distance and then use the Drop % as an anchor on the Lmax marker.
Break % Drop
Break Rate
Split Graph - Data View Finding Break load using a % Drop in load after Lmax
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