Coupon Compression Testing

PythonCompositesMachiningASTM D695Data Analysis

Standardized compression testing of six fiberglass laminates to select the Polaris rocket airframe material.

Laminates tested: 6
Test system capacity: 15 kN

Problem

Select a fiberglass laminate for the Polaris rocket airframe based on compression performance and material cost.
Compare six laminate configurations under standardized mechanical testing conditions.

Approach

Machined a Boeing BSS 7260 fixture and prepared test coupons.
Performed standardized compression testing (ASTM D695 / DIN EN 2850) on six fiberglass laminates using a 15 kN-capacity system.
Developed a Python pipeline to convert load/displacement data into stress-strain curves and extract failure properties.

Result

Generated quantitative compression data for six laminate configurations, enabling comparison of their mechanical performance for airframe material selection.

Testing

I compression-tested six fiberglass laminate configurations for the Polaris rocket airframe, following ASTM D695 / DIN EN 2850 procedures on a 15 kN-capacity testing system. The aim was to compare their mechanical performance so a laminate could be selected on compression performance and material cost.

Fixture and specimens

I machined a Boeing BSS 7260 compression-testing fixture from technical drawings using manual milling and lathe operations, holding tight tolerances so coupons align consistently. I also manufactured precision aluminum alignment tabs on a CNC waterjet to support standardized testing.

The machined aluminum compression-testing fixture with four socket-head cap screws, holding a coupon — The machined compression-testing fixture with a coupon clamped in place.

Boeing BSS 7260 compression-testing fixture drawing — Fixture drawing (Boeing BSS 7260).

Data pipeline

I wrote a Python pipeline that converts raw load and displacement data into stress-strain curves and extracts key failure properties, so all six laminates can be compared quantitatively and repeatably.

Raw time, crosshead displacement and load data exported from the test system — Raw time, crosshead and load export from the test system.

Stress versus strain curves for the six laminates A1 to A6 — Stress vs. strain for the six laminates (A1–A6) from the Python pipeline. Red dots mark each laminate's peak stress.

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