A photographic impact testing machine for measuring the varying intensity of an impulsive force

Dunn, B.

doi:10.1016/s0016-0032(98)90255-1

Cited by 8 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2. 1 The strain gauges are mounted near the striking edge and are protected by a mechanical cover. The strain gauge bridge circuit (discussed in Sec.…”

Section: Mechanical Design Considerationsmentioning

confidence: 99%

“…Instrumented impact testing is often considered to be a relatively recent technical development of Charpy testing, even though the earliest known paper dealing with force measurements during an impact test [1] actually predates the first pendulum machine publication [2] by 1 year. The analysis of an instrumented Charpy test consists of the determination of characteristic time, force, displacement, and absorbed energy 1 • calculation of dynamic fracture toughness in the ductile-to-brittle transition region (see American Society for Testing and Materials [ASTM] E1921, Annex A1 [3]) or in the fully plastic regime (see ASTM E1820, Annex A17 [4]);…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Design Considerations to Improve Charpy Instrumented Strikers

Vlajic

Chijioke

Lucon

2020

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

Instrumented impact testing allows the applicability of conventional Charpy tests to be extended toward assessing mechanical properties such as dynamic fracture toughness and dynamic tensile properties. In this work, we present design considerations for engineering instrumented strikers for Charpy V-notch impact testing. Specific attention is given to the mechanical and geometric features, as well as the placement of strain gauges and corresponding bridge circuits for instrumentation. These design considerations are intended to make the sensitivity invariant to the location and distribution of impact forces. The concepts presented in this work were applied to an actual instrumented striker, which was then statically calibrated. Data from this calibration indicate that the device has good repeatability, shows a linear response, and is relatively insensitive to impact location.

show abstract

“…2. 1 The strain gauges are mounted near the striking edge and are protected by a mechanical cover. The strain gauge bridge circuit (discussed in Sec.…”

Section: Mechanical Design Considerationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Design Considerations to Improve Charpy Instrumented Strikers

Vlajic

Chijioke

Lucon

2020

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

show abstract

“…Over the past few years, many efforts have been made to develop the experimental apparatus that can characterize the deformation response of materials at different strain rates . Conventional servo‐hydraulic and screw‐driven machines are sufficient to meet the requirement for quasi‐static (from 10 −4 to 10 0 s −1 ) experiments, while experiments at intermediate strain rate (from 10 0 to 10 2 s −1 ) are generally carried out on machines based on hydraulic, dropping weights or fly wheel . For dynamic loading (from 10 2 to 10 6 s −1 ) experiments, Split Hopkinson Pressure Bar apparatus and Taylor impact are two common techniques, although an inhomogeneous strain and a non‐constant strain rate are difficult to avoid.…”

Section: Introductionmentioning

confidence: 99%

Structural origin for the strain rate dependence of mechanical response of fluoroelastomer F2314

Chang

Lin

Chen

et al. 2019

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

The structural evolution of fluoroelastomer F2314 is studied during uniaxial tensile in a large strain rate range (0.1–150 s−1) with the combination of a homemade high‐speed stretching device and in situ small‐ and wide‐angle X‐ray scattering techniques. Based on the mechanical behaviors and structural evolutions, three strain rate regions (I–III) are defined. The microphase‐separated structure plays an important role in the mechanical response of F2314. In Region I, deformation of soft domains is the main process before yielding, accompanied by the destruction of lamellar crystals in hard domains. In the stress plateau zone, deformation of hard domains is confirmed as the primary mechanism of energy dissipation. With the orientation parameter of the amorphous phase reaching a critical value, strain hardening is triggered. Recrystallization also takes place in strain hardening zone. In Region II, due to the mismatch between the mobility of molecular chains in hard domains and the acting time of stress, large deformation of hard domains is more and more difficult to occur with the disappearance of recrystallization. In Region III, as almost all molecular chains have no time to adjust or relax to fit the stress field, the sample presents a brittle fracture. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 607–620

show abstract

The Origins of the Hopkinson Bar Technique

Walley

2018

The Kolsky-Hopkinson Bar Machine

View full text Add to dashboard Cite

A photographic impact testing machine for measuring the varying intensity of an impulsive force

Cited by 8 publications

References 0 publications

Design Considerations to Improve Charpy Instrumented Strikers

Design Considerations to Improve Charpy Instrumented Strikers

Structural origin for the strain rate dependence of mechanical response of fluoroelastomer F2314

The Origins of the Hopkinson Bar Technique

Contact Info

Product

Resources

About