Localized material yielding and pin deformation introduce extraneous structural displacement, masking true bearing yield strength.
Deploy a dedicated dual-extensometer assembly clamped directly onto the specimen edge flanking the loading pin.
Measure both the pin outer diameter and hole inner diameter to the nearest 0.01mm to document exact clearance values.
Measure both the pin outer diameter and hole inner diameter to the nearest 0.01mm to document exact clearance values.
Proper clevis-to-pin clearance ensures pure bearing stress distribution without edge jamming.
Use hardened pins exclusively; soft steel pins will bend elastically and introduce invalid displacement signals.
Calculating displacement from total crosshead travel instead of direct-on-sample extensometers.
Typical testing system controllers rely on 24-bit resolution. Under high-accuracy flexural analysis, this creates a data phenomenon called **”stair-stepping”** or quantization error. When trying to track minor micro-deflection in rigid polymers, 24-bit electronic circuits suffer from resolution limits, dropping critical transition points during initial load curves.
Newton Characterization™ architecture utilizes a 32-bit analog-to-digital processor converter. This increases measurement fidelity by a factor of 256x, outputting 4.29 billion discrete signal thresholds. Electrical chatter is actively muted under a dedicated 100,000:1 Signal-to-Noise Ratio (SNR).
Comparing standard 24-bit quantization with Newton™ 32-bit resolution
Observe the stepped resolution blocks in the legacy 24-bit curve (Red) versus the absolute **analog-smooth response curve** captured by Newton™ 32-bit architectures (Green). This fidelity is what prevents mechanical data variance during modulus evaluation.
Expert Engineering Commentary
Core Problem Identification
Elongation or ovalization of the hole structure before ultimate bulk tensile or shear edge breakout.
Root Cause Analysis
Pin bending or micro-clearance gap slippage within the load frame coupling causing non-linear initial loading artifacts.
Hardware Specific Solutions
Hardened tool steel clevis fixture with matched precision ground loading pins and automatic self-centering pull rods.