scholarly journals Approximated Evaluation of Load History by Soft Body Impact.

1999 ◽  
Vol 65 (635) ◽  
pp. 1615-1621
Author(s):  
Tadaharu ADACHI ◽  
Satoshi YAMAMURA ◽  
Masahiro ARAI ◽  
Hiroyuki MATSUMOTO
Keyword(s):  
Load History ◽  
Soft Body ◽  
Approximated Evaluation

Application of the Strip Yield Model to Crack Growth Predictions for Structural Steel

2010 ◽  
Vol 57 (1) ◽  
pp. 1-20
Author(s):  
Małgorzata Skorupa ◽  
Tomasz Machniewicz
Keyword(s):  
Structural Steel ◽  
Crack Growth ◽  
Model Calibration ◽  
Load History ◽  
Yield Model ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Constraint Factors ◽  
Strip Yield Model ◽  
Closure Mechanism

Application of the Strip Yield Model to Crack Growth Predictions for Structural SteelA strip yield model implementation by the present authors is applied to predict fatigue crack growth observed in structural steel specimens under various constant and variable amplitude loading conditions. Attention is paid to the model calibration using the constraint factors in view of the dependence of both the crack closure mechanism and the material stress-strain response on the load history. Prediction capabilities of the model are considered in the context of the incompatibility between the crack growth resistance for constant and variable amplitude loading.

scholarly journals Failed prey or peculiar necrolysis? Isolated ammonite soft body from the Late Jurassic of Eichstätt (Germany) with complete digestive tract and male reproductive organs

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Christian Klug ◽  
Günter Schweigert ◽  
Helmut Tischlinger ◽  
Helmut Pochmann
Keyword(s):  
Digestive Tract ◽  
Late Jurassic ◽  
Reproductive Organs ◽  
Mantle Cavity ◽  
Soft Body ◽  
Exceptional Preservation ◽  
Attachment Structures ◽  
Male Reproductive Organs ◽  
Marine Basins

AbstractAmmonoid soft parts have been rarely described. Here, we document the soft parts of a perisphinctid ammonite from the early Tithonian of Wintershof near Eichstätt (Germany). This exceptional preservation was enabled by the special depositional conditions in the marine basins of the Solnhofen Archipelago. Here, we document this find and attempt to homologize its parts with various organs such as the digestive tract, reproductive organs, the mantle cavity with gills, and the hyponome, with differing degrees of reservation. Alternative interpretations are also taken into account. We suggest that the soft parts were separated from the conch either taphonomically (following necrolytical processes affecting the attachment structures) or during a failed predation, where a predator (fish or coleoid) removed the soft parts from the conch but then dropped them. This find is interesting because it adds to the knowledge of ammonite anatomy, which is normally hidden in the conch. The reproductive organs show traces of what might have been spermatophores, thus supporting the hypothesis that the microconchs represented the males.

scholarly journals Do air-gaps behind soft body armour affect protection?

2017 ◽  
Vol 164 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Lee Tilsley ◽  
D J Carr ◽  
C Lankester ◽  
C Malbon
Keyword(s):  
Ceramic Composite ◽  
Air Gap ◽  
The Body ◽  
Gap Size ◽  
Soft Body ◽  
Air Gaps ◽  
Body Armour ◽  
Ballistic Protection ◽  
Back Face ◽  
Full Metal Jacket

IntroductionBody armour typically comprises a fabric garment covering the torso combined with hard armour (ceramic/composite). Some users wear only soft armour which provides protection from sharp weapons and pistol ammunition. It is usually recommended that body armour is worn against the body with no air-gaps being present between the wearer and the armour. However, air-gaps can occur in certain situations such as females around the breasts, in badly fitting armour and where manufacturers have incorporated an air-gap claiming improvements in thermophysiological burden. The effect of an air-gap on the ballistic protection and the back face signature (BFS) as a result of a non-perforating ballistic impact was determined.MethodsArmour panels representative of typical police armour (400x400 mm) were mounted on calibrated Roma Plastilina No 1 and impacted with 9 mm Luger FMJ (9×19 mm; full metal jacket; Dynamit Nobel DM11A1B2) ammunition at 365±10 m/s with a range of air-gaps (0–15 mm). Whether or not the ammunition perforated the armour was noted, the BFS was measured and the incidence of pencilling (a severe, deep and narrow BFS) was identified.ResultsFor 0° impacts, a critical air-gap size of 10 mm is detrimental to armour performance for the armour/ammunition combination assessed in this work. Specifically, the incidences of pencilling were more common with a 10 mm air-gap and resulted in BFS depth:volume ratios ≥1.0. For impacts at 30° the armour was susceptible to perforation irrespective of air-gap.ConclusionsThis work suggested that an air-gap behind police body armour might result in an increased likelihood of injury. It is recommended that body armour is worn with no air-gap underneath.

On the Measurement of Material Creep Parameters by Nanoindentation

2004 ◽  
Vol 841 ◽  
Author(s):  
J. A. LaManna ◽  
W. C. Oliver ◽  
G. M. Pharr
Keyword(s):  
Material Constant ◽  
Uniaxial Stress ◽  
Complete Characterization ◽  
Indentation Load ◽  
Amorphous Selenium ◽  
Load History ◽  
Time Data ◽  
Creep Equation ◽  
Uniaxial Creep ◽  
Material Creep

ABSTRACTPrevious studies of how material creep parameters can be measured by nanoindentation testing have focused mostly on measurement of the stress exponent for creep, n, and the activation energy, Qc. However, a more complete characterization requires that the material constant A in the uniaxial creep equation εu =Aσn (where εu is the uniaxial strain rate and σ is the uniaxial stress) also be evaluated. Here, we begin to address this issue by performing simple nanoindentation creep experiments in amorphous selenium at temperatures above and below the glass transition. At 35°C and above, the material exhibits a simple linear viscous creep behavior that is load history independent. This allows the parameter A to be determined from the indentation load-displacement-time data by means of an analytical solution. To examine the validity of the approach, values of the parameter A measured in nanoindentation tests are compared to independent measurements obtained in uniaxial tension creep experiments.

Modelling soft body impact on composite structures

2003 ◽  
Vol 61 (1-2) ◽  
pp. 103-113 ◽  
Author(s):  
Alastair F. Johnson ◽  
Martin Holzapfel
Keyword(s):  
Composite Structures ◽  
Soft Body

scholarly journals Assessment of the Deterioration State of Post-Installed Bonded Anchors Using Ultrasonic

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2077
Author(s):  
Oliver Zeman ◽  
Michael Schwenn ◽  
Martin Granig ◽  
Konrad Bergmeister
Keyword(s):  
Maximum Load ◽  
Assessment Method ◽  
Load Level ◽  
Experimental Investigations ◽  
Load History ◽  
Anchor System ◽  
Ultrasonic Methods ◽  
Building Maintenance ◽  
History Of ◽  
Set Up

The assessment of already installed anchorages for a possible exceeding of the service load level is a question that is gaining more and more importance, especially in building maintenance. Bonded anchors are of particular interest here, as the detection of a capacity reduction or load exceedance can cause damage to the concrete-bonded mortar behavior. This article investigates the extent to which ultrasonic methods can be used to make a prediction about the condition of anchorages in concrete and about their load history. A promising innovative assessment method has been developed. The challenges in carrying out the experimental investigations are the arrangement of the transducers, the design of the test set-up and the applicability of direct, indirect or semidirect ultrasonic transmission. The experimental investigations carried out on a test concrete mix and a bonded anchor system show that damage to the concrete structure can be detected by means of ultrasound. The results indicate the formation of cracks and therefore a weakening of the response determined by means of direct, indirect and semidirect ultrasonic transmission. However, for application under non-laboratory conditions and on anchors with unknown load history, the calibration with a reference anchor and the identification of the maximum load is required. This enables a referencing of the other loaded anchors to the unloaded conditions and allows an estimation of the load history of individual anchors.

Sign in / Sign up

Export Citation Format

Share Document