A method for analyzing fatigue life of an elastomeric component includes a step of conducting a finite element analysis to obtain a base state. A plurality of case vectors are then selected to represent a space of possible loading states that occur within a time-varying load data signal based on measurement of the elastomeric component or vehicle dynamics. For at least a portion of the case vectors, a finite element analysis is conducted at a plurality of discrete gridpoints along the case vectors starting at the base state and tracking the case vector. Using an interpolation engine, desired local solution variables for a current state may be interpolated from the finite element analysis at the plurality of discrete gridpoints. A damage calculation may then be calculated based on the desired local solution variables for the current state.

Analysis of residual stress in materials is often done in static conditions in a laboratory. Accurate systems and methods for performing these analyses in a dynamic, non-laboratory environment are notoriously difficult and can be very inaccurate. A method using a portable, field deployable apparatus having greater accuracy than currently available is disclosed whereby accurate and repeatable residual stress analysis may be implemented in non-laboratory environments leading to greatly improved diagnostics, maintenance and life limit prediction.

A method for testing an arresting unit (15) for locking a foldable wing tip portion (11) to a wing (5) that includes a fixed wing (9), a foldable wing tip portion (11), and a folded position, an actuation unit (13) for actuating movement of the foldable wing tip portion (11), and an arresting unit (15) for locking the foldable wing tip portion (11). The method includes: locking the foldable wing tip portion (11) in the extended position by the arresting unit (15), controlling the actuation unit (13) to move the foldable wing tip portion (11) in the direction towards the folded position, such that the foldable wing tip portion (11) urges against the arresting unit (15) with a predefined test load, detecting deformation of the arresting unit (15) during or after application of the test load, and comparing the detected deformation to a predefined threshold deformation.

Methods and apparatuses for multiple degree-of-freedom fatigue testing of a specimen. The apparatus includes a first platform, a second platform, a plurality of actuator assemblies, a load cell, a mounting plate, a specimen support, a direct-strain imaging system, and a local sense and control system. Each actuator assembly includes a servo-control, a position encoder, and a piston that is constructed to move in a linear direction in accordance with the servo-control. Each piston is rotatably connected to the second platform. The load cell is connected to the second platform and constructed to output force measurements in three orthogonal directions and torque measurements about the three orthogonal directions. The mounting plate is constructed to hold a portion a specimen. The specimen support is constructed to hold another portion of the specimen. The direct-strain-imaging system includes a camera that is constructed to record a plurality of images of the specimen during fatigue testing. The local sense and control system constructed to receive: a loading specification, the force measurements and torque measurements from the load cell, and position information from each position encoder, and output control commands to each servo-control of the plurality of actuator assemblies based on the received loading specification. The control commands are updated in time in accordance with the position information from each position encoder and the force measurements and torque measurements from the load cell.

The invention relates to an arrangement and to a method for the synchronous determination of the shear modulus and of the Poisson's number on samples of elastically isotropic and anisotropic materials. In the arrangement, an indenter is movable in parallel with its longitudinal axis (A) in the direction of the surface of a sample such that a force action is exerted on the material by its tip. The force can be determined by a device for measuring this force and the indenter is additionally deflected in translation along at least one further axis. The longitudinal axis (A) of the indenter is aligned at an angle 90 with respect to the surface of the sample and the indenter carries out an upward movement and a downward movement. In this respect, a device is present for calculating the shear modulus G and the Poisson's number v from the contact stiffness k determined in this manner, from the acting normal force P, from the indentation modulus M.sub.S and from the shear modulus-related parameter N.sub.S of the sample while taking account of the respective angle .

A system and method for testing a material system may include a support structure for mounting the material system, and a electromechanical device operably connected to the support structure, wherein the electromechanical device applies an electromechanical-induced force to the material system, and wherein the electromechanical-induced force causes a displacement in the material system equivalent to material displacement from thermal stress in significantly less time.

A system for testing fatigue performance of material in low-temperature liquid hydrogen environment, which relates to the technical field of mechanical property test platforms, includes a jacket cover. A hydrogen sensor is provided at the top of and within the jacket cover; a rack, a liquid hydrogen tank and a liquid nitrogen tank are provided in the jacket cover; a loading mechanism and a liquid hydrogen containing mechanism are provided on the rack, the loading mechanism is connected to the rack, and the bottom of the loading mechanism extends into the liquid hydrogen containing mechanism; the liquid hydrogen tank and the liquid nitrogen tank both communicate with the liquid hydrogen containing mechanism; and the loading mechanism is configured for providing tension or pressure to a sample. The liquid hydrogen containing mechanism is provided with a cooling channel located around a sealing gasket, the cooling channel communicates with a thermostat.

A stress corrosion crack test method for evaluating the stress corrosion crack susceptibility of a steel material in alcohol. The method includes filling a cell containing a uniaxial tensile test piece of the steel material with an alcohol solution containing carboxylic acid: 0.1 mmol/L or more and less than 40 mmol/L, chloride ions: 0.05 mg/L or more and less than 300 mg/L, and water: 0.1 vol. % or more and less than 5 vol. %. Additionally, the method includes applying a fluctuating stress at a frequency of 2.010.sup.5 Hz or more and 2.010.sup.2 Hz or less to the uniaxial tensile test piece in the tensile direction. The maximum stress being equal to or more than the yield strength and less than the tensile strength at a test solution temperature, and the minimum stress being 0% or more and 90% or less of the yield strength.

Disclosed is a method of measurement and determination on fracture toughness of structural materials at high temperature, comprising: preliminary assessing the ductility of a material based on a high-temperature uniaxial tensile test and the fracture characteristic; designing and manufacturing a CT specimen; conducting a monotonic loading fracture test on the CT specimen at high temperature; modifying a load-displacement curve output by a testing machine; determining a passivation coefficient M for the crack of the structural material; reversely recursing instant load-displacement data pairs corresponding to the instant crack length; calculating a J_R crack extension resistance curve of the tensile test; examining the validity of the J_R crack extension resistance curve and the fracture toughness J.sub.IC; calculating the fracture toughness per equivalent of the structural material K.sub.IC. The present invention overcomes the difficulty of placing an extensometer inside a high-temperature furnace.

The present invention relates to a method for detecting temporally varying thermomechanical stresses and/or stress gradients over the wall thickness of metal bodies, in particular pipelines. In the method, the temperature on the outer surface of the body is measured in order to determine a temperature progression and stress progression therefrom. In addition, electromagnetic ultrasonic transducers are used at at least one measuring point on the outer surface in order to determine the progression of the stresses and/or stress gradients over time over the wall thickness of the body in conjunction with the result of the temperature measurement. The method allows the fatigue monitoring of pipelines even in the event of rapid stress changes.