Fatigue

High operating temperatures, harsh environments and excessive cycling can cause significant decreases in elastomeric material durability.  ARDL performs tests to measure the cycling fatigue of materials and products to determine fatigue life and predict damage initiation once failure criteria has been established.  Our capabilities include DeMattia Fatigue, Mini-DeMattia Fatigue and Dynamic Fatigue tests using MTS servohydraulic machines.  With this equipment, we are able to measure the number of flexural cycles or load deformation cycles a polymer material can withstand before damage occurs and in some cases, use this data for service life prediction of a part.  We can review crack-growth, measure strain and load, set specific loads and cycles, test at elevated temperatures and perform tests on ASTM specimens as well as specimens from field service parts.

DeMattia Fatigue Testing

The DeMattia Fatigue test is a dynamic test measuring the resistance of a material to cracking.  This cracking is performed by flexural extension or bending.  The number of cycles is measured and the crack growth or resistance to crack growth is determined.

Mini-DeMattia Testing

The Mini DeMattia flex-life test determines the durability of a component and can be used to measure the change in durability as a function of age.   A major benefit of the ARDL developed procedure is the ability to perform the traditional DeMattia test on scaled down samples as thin as 0.30" that are prepared from new or aged field samples.

Pure Shear Fatigue Crack Growth Testing

Utilizing pure shear cut growth test specimens, ARDL monitors crack growth rates with automated digital photography. The crack growth rates are compared with servohydraulic output of load, displacement, and strain to obtain a dc/dN v. T (crack growth rate versus tear energy) curve at various temperatures and loading profiles to characterize crack propagation behavior.

Customized Fatigue Testing

In some instances, specimens are too large for the DeMattia equipment or special fixturing is needed. In these cases, ARDL utilizes its MTS and other servohydraulic load frames for dynamic characterization of elastomeric parts as well as for stroke and load control fatigue testing. We are able to measure the properties of materials for a predetermined number of cycles and also at elevated temperatures with customized fixtures.
 

Available Methods

Crack Resistance

Standard Test Method for Rubber Deterioration-Crack Growth

ASTM D 813

DeMattia Flex Testing

Standard Test Methods for Rubber Deterioration—Dynamic Fatigue

ASTM D 430 Method B

Demattia Flex Testing

Physical Testing Methods For Vulcanized Rubber

JIS K 6301

Dynamic Fatigue - DeMattia Flexometer

Standard Test Methods for Rubber Deterioration - Dynamic Fatigue

ASTM D 430

Flex Resistance (DeMattia)

Flex Resistance Using DeMattia Flex

Toyota TSM 1500G

Flexible Cellular Materials Testing - Latex Foam

Standard Specifications for Flexible Cellular Materials - Latex Foam

ASTM D 1055 (except Sec. 20-23)

Flexible Transition Couplings Testing

Standard Specification for Flexible Transition Couplings for Underground Piping Systems

ASTM C 1173 (Table 1, excluding D 3045)

Flexural Properties of Plastics - Method A, Single Speed Test

Plastics - Determination of Flexural Properties

ISO 178

Flexural Properties of Plastics - Procedure A, Small Deflection

Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials

ASTM D 790 - Method A

Flexural Properties of Plastics - Procedure B, Large Deflection

Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials

ASTM D 790 - Method B

Fluid Resistance of Gasket Materials - Flexibility

Fluid Resistance of Gasket Material - Flexibility

ASTM F 146

Goodrich Flexometer - Method A

Standard Test Methods for Rubber Property - Heat Generation and Flexing Fatigue In Compression - Method A: Heat Build-Up Conditions and Blow-Out Conditions

ASTM D 623

Goodrich Flexometer - Method A

Standard Test Methods for Rubber Property - Heat Generation and Flexing Fatigue In Compression - Method A: Heat Build-Up Conditions and Blow-Out Conditions

ASTM D 623

Latex Condoms - Flexible Packaging

Male Latex Condom - Requirements and Test Methods

WHO 2004

Latex Condoms - Flexible Packaging

Natural Rubber Latex Male Condoms - Requirements and Test Methods

ISO 4074-1

Low Temperature Flex Properties - Tape Sealants

Standard Test Method for Low-Temperature Flexibility of Preformed Tape Sealants

ASTM C 765

Ross Flexometer

Standard Test Method for Measuring Rubber Deterioration - Cut Growth Using Flexing Apparatus.

ASTM D 1052