Failure Analysis
Fracture Toughness and
Fatigue Testing
Scroll Down to Explore
Any material can undergo toughness fracture and fatigue when in use over time and subjected to enough force, impact, loading cycles, or harsh environment. Failure analysis helps us to identify and determine the primary causes leading to the failure of material or end products. It also helps us prevent future failure occurrences.
The Fracture Toughness Test determines how well a material can resist the growth of a crack under an increasing load. The fracture toughness values identified by the test are helpful in material selection and determining the risk of component failure in case of a flaw in an existing structure.
Microlab can test various specimen geometries such as Compact Tension (CT), Bend Specimen (SEB), Disk-Shaped (DCT), Arc-Shaped Tension (AT), and Arc-Shaped to Bend (AB).
- Capability to handle specimens of many sizes
- Onsite machining and Specimen preparation
- Customized test setups and fixtures
- Computer data acquisition for accurate and timely results
- Customized servo-hydraulic equipment to perform the test
KIC Testing
Linear-Elastic Plane-Strain Fracture Toughness
The Fracture toughness testing process adheres to ASTM E399 and involves a continuous increase in load to the specimen and determines the critical stress intensity KIc. This test method is the KIC test, KIC, or K1C fracture toughness test. It is a widely used test, particularly in aerospace industry standards.
Test Methods
- ASTM E399, B645, B646, B909
- ISO 12135
- BS 7448-1
- ASTM E2818 (For welds)
- ISO 15653 (For welds)
- BS 7448-2 (For welds)
JIC Testing
Elastic-Plastic Fracture Toughness
During the testing of ASTM E1820, we apply a rising load with periodic partial unloading to measure the crack length as the test progresses. Since this method takes measurements throughout the test, it provides rich data on the material’s behavior as the crack opens. It is often possible to get valid results where a KIc test may not be feasible.
Test Methods
- ASTM E1820
- ISO 12135
- BS 7448-1
- ASTM E2818 (For welds)
- ISO 15653 (For welds)
- BS 7448-2 (For welds)
CTOD Testing
Crack Tip Opening Displacement test
The Crack Tip Opening Displacement or CTOD Test measures the resistance of a material to the propagation of a crack. We use CTOD on materials that can show some plastic deformation before failure occurs, causing the tip to stretch open. Accurate measurement of this displacement is one of the essentials of the test.
Test Methods
- ASTM E1820
- ISO 12135
- BS 7448-1
- ASTM E2818 (For welds)
- ISO 15653 (For welds)
- BS 7448-2 (For welds)
Fatigue Crack Growth Rate
Fatigue Crack Growth Rate (da/dN) Test helps determine the cracking rate under specified loading conditions once we initiate a flaw in the specimen. The graph of Cyclic Stress plots against the Crack Growth Rate, with stress intensity being the controlling variable.
Fatigue Crack Growth Rate Results generates a report in both tabular and graphical formats. It also gives the Paris Law and threshold values. The graphs include da/dN vs. ΔK and Crack Length vs. Cycles.
Test Methods
- ASTM E647
- ISO 12108
Low Cycle Fatigue Testing
Low cycle fatigue (LCF) is low-cycle endurance testing, where we subject components to mechanical cyclic plastic strains that cause fatigue failure within a short number of cycles.
The low-cycle fatigue test is usually run slowly with a relatively short number of cycles to failure. LCF test charecterizes high amplitude and low-frequency plastic strains.
Test Methods
- ASTM E606
- ASTM E466
- ISO 12110
Reinforcement Coupler Testing
We do this test adhering to the 16172 standards for reinforcement couplers for mechanical splices in concrete.
The tests are:
- Static tensile test
- Slip test
- Cyclic tensile test
- Fatigue test
- High cycle fatigue test
- And other tests in ASME sec-2
Test Methods
- IS 16172
- ISO 15835