Flexural testing, commonly referred to as bend testing, is a fundamental mechanical procedure used to determine the flexural strength and stiffness of a material. This configuration is essential for evaluating brittle or semi-rigid materials such as ceramics, composites, plastics, and timber. Unlike tensile testing, flexural testing induces both tensile and compressive stresses within the specimen simultaneously.
Technical Configuration and Test Modes
TRI flexural systems are typically configured in one of two standard modes on our Universal Testing Machines (UTM):
- 3-Point Bend: The specimen is supported on two fixed points while a single loading nose applies force at the midpoint. This is the primary method for determining flexural modulus and strength.
- 4-Point Bend: This configuration utilizes two loading noses to apply force, creating a region of “pure bend” between the two points. This reduces the influence of shear stress and is often preferred for materials with high variability or non-homogeneous structures.
System Series & Frame Selection
The flexural configuration is implemented across our primary load frame series depending on the required force and specimen size:
- 100 Series: Utilized for standard material testing where loads do not exceed 2,250 lbf.
- 200 Series: A specialty configuration characterized by long travel, ideal for specimens requiring significant deflection.
- 300 & 600 Series: Utilized for high-capacity requirements or structural components, scaling from 1,125 lbf to 2000 kN.
Interface Integration & Data Acquisition
- Standardized 16mm Interface: For applications up to 20 kN (4,500 lbf), TRI systems utilize a 16mm (16M/16F) interface. This ensures the loading nose remains axially aligned with the support base and allows operators to transition from tensile to flexural setups without custom mounting hardware.
- Newton Controller: Manages the synchronized acquisition of load and displacement data.
- Advanced Deflection Tracking: For high-accuracy data required by standards like ASTM D790, the Newton Controller supports secondary channels for deflectometers or clip-on extensometers to measure specimen strain directly.
Common Standards Supported
TRI equipment is engineered to execute protocols in accordance with international standards, including plastics testing standards such as ASTM D790, ISO 178 , and ASTM D6272, ISO 14125 fiber reinforced composites and ASTM C1161 for advanced ceramics.