Experimental and Applied Mechanics

The Influence of Sample Thickness on the DCDC Fracture Test (Experimental and Applied Mechanics)

ABSTRACT The double cleavage drilled compression (DCDC) fracture test uses axial compression to drive stable cracks in glasses and brittle polymers. The cracks are generated by regions of tension in a rectangular column of material containing a central hole. The observed relationship between crack length and the applied axial stress is fitted with a two-dimensional […]

Analysis of Hysteresis Damage Accumulation and the Effect on Fatigue Life (Experimental and Applied Mechanics)

ABSTRACT In order to validate an existing energy-based fatigue life prediction understanding, the strain energy accumulation for interrupted loading cycles was analyzed. The life prediction method being validated was developed based on the understanding that strain energy density accumulated during monotonic fracture is a physical damage quantity that is equal to total cumulative hysteresis strain […]

Fatigue Improvement of Welded Elements by Ultrasonic Impact Treatment (Experimental and Applied Mechanics) Part 1

ABSTRACT The ultrasonic impact treatment (UIT) is one of the new and promising processes for fatigue life improvement of welded elements and structures. In most industrial applications this process is known as ultrasonic peening (UP). The beneficial effect of UIT/UP is achieved mainly by relieving of harmful tensile residual stresses and introducing of compressive residual […]

Fatigue Improvement of Welded Elements by Ultrasonic Impact Treatment (Experimental and Applied Mechanics) Part 2

Ultrasonic Peening of HSS Welded Elements 700 MPa yield strength steel Four series of large-scale welded samples were subjected to fatigue testing to evaluate the effectiveness of UIT/UP application for fatigue life improvement of welded elements made from 350 MPa and 700 MPa yield strength steels [13]. The fatigue specimens were designed as 80 mm […]

Delamination between Functionalized Silicon Surfaces (Experimental and Applied Mechanics)

The paper describes the development of an experiment with associated analysis to determine the toughness of a molecular adhesive formed by bringing together two functionalized silicon surfaces. Si (111) surfaces were coated with amine and carboxy-terminated self-assembled monolayers (SAMs). The areal density of these termini was varied in order to modulate the bonding interactions between […]

Failure and Fracture Behavior of Brittle Polymer Foam (Experimental and Applied Mechanics) Part 1

ABSTRACT Experimental study was performed to investigate the fracture behavior of relatively brittle polymer foam. A single notch bending specimen made of a PVC core cell foam A-series, A 800 and A 1200, are used for the investigation. To measure the strain around the defect section, a 2D digital image correction (DIC) technique was used. […]

Failure and Fracture Behavior of Brittle Polymer Foam (Experimental and Applied Mechanics) Part 2

RESULTS AND DISCUSSIONS TENSILE STRENGTH The tensile load measured directly through the load cell was used to calculate the tensile strength and the average of strains along the defect section obtained from the DIC was used to calculate the corresponding strain. The net section strength, in the case of a specimen with sharp cracks, a […]

Crack Growth in Three-Point Bend Specimens Made of Polymeric Foams (Experimental and Applied Mechanics)

ABSTRACT The problem of crack growth in a three-point bend specimen made of polymeric foams is investigated. Polymeric foams are anisotropic materials and cracks, generally, propagate under mixed-mode loading. The axes of material anisotropy are inclined with respect to the crack plane. Due to the anisotropy of the material crack kinking occurs even though the […]

Reliability Evaluation of Conformal Coatings for Tin Whisker Failure Mitigation in Accelerated Testing Conditions (Experimental and Applied Mechanics)

Abstract Tin whisker growth has become a reliability concern during the course of Pb-free solder transition. A common mitigation strategy is to use conformal coatings to prevent electrical shorts by tin whiskers. However, recent research indicates that under elevated temperature and humidity, or in areas of thin covering, whiskers can grow and penetrate conformal coatings. […]

Investigation of Manganese Cobalt Oxide (MCO) Coatings on Fuel Cell Interconnects (Experimental and Applied Mechanics)

ABSTRACT Planar Solid Oxide Fuel Cells (SOFCs) are composed of repeating cathode-electrolyte-anode units separated by electrically conductive interconnects. With the reduction in fuel cell operating temperature to approximately 800°C, it has become possible to use chromium-based, ferritic stainless steel or Crofer for interconnects. These interconnects must survive the high temperature oxidizing and reducing environments while […]