Effect of initial delamination on Mode 1 and Mode 2 interlaminar fracture toughness and fatigue fracture threshold

Static and fatigue double-cantilever beam (DCB) and end-notch flexure (ENF) tests were conducted to determine the effect of the simulated initial delamination in interlaminar fracture toughness, G(sub c), and fatigue fracture threshold, G(sub th). Unidirectional, 24-ply specimens of S2/SP250 glass/epoxy were tested using Kapton inserts of four different thickness - 13, 25, 75, and 130 microns, at the midplane at one end, or with tension or shear precracks, to simulate an initial delamination. To determine G(sub c), the fatigue fracture threshold below which no delamination growth would occur in less than 1 x 10(exp 6) cycles, fatigue tests were conducted by cyclically loading specimens until delamination growth was detected. Consistent values of model 1 fracture toughness, G(sub Ic), were measured from DCB specimens with inserts of thickness 75 microns or thinner, or with shear precracks. The fatigue DCB tests gave similar values of G(sub Ith) for the 13, 25, and 75 microns specimens. Results for the shear precracked specimens were significantly lower that for specimens without precracks. Results for both the static and fatigue ENF tests showed that measured G(IIc) and G(IIth) values decreased with decreasing insert thickness, so that no limiting thickness could be determined. Results for specimens with inserts of 75 microns or thicker were significantly higher than the results for precracked specimens or specimens with 13 or 25 microns inserts

He Versus She: A Gender Specific Analysis of Legal and Extralegal Effects on Pretrial Release for Felony Defendants

The current study seeks to identify significant predictors of pretrial processing for both male and female defendants in an aggregate sample. The data used in this study is taken from the State Court Processing Statistics (SCPS), 1990-2000: Felony Defendants in Large Urban Counties (Bureau of Justice Statistics 2004). The original sample included a total of 87,437 felony cases. The relationship between relevant independent variables and five separate dependent variables (denial of bail, non-financial release, amount of bail set, making bail, and pretrial incarceration) were analyzed using both multivariate regression and Z-score comparisons within gender-specific models. Findings suggest that effects of certain independent variables on pretrial release decisions and outcomes are different between the gender-specific models

“That is Not Behavior Consistent with a Rape Victim”: The Effects of Officer Displays of Doubt on Sexual Assault Case Processing and Victim Participation

Despite the prevalence and severity of sexual violence, case attrition has been identified as a significant issue. Of the cases that are reported to police, only a small portion result in arrest, prosecution, or conviction. Research has revealed that much of this attrition occurs early in the process and that a number of theoretically supported legal (e.g., physical evidence, victim participation) and extralegal (e.g., demographics, victim credibility) factors influence how and whether a case progresses through the criminal justice system. However, few researchers have directly examined the impact of officer doubt on case processing. Whereas legal and extralegal factors represent case characteristics, doubt represents officer cognition about these characteristics. These perceptions can affect how victims are treated, how police investigate the case, and ultimately, the case’s progression through the system. A random sample of sexual assault reports from one police department in a medium-sized jurisdiction in the western U.S. was drawn to examine the expression of officer doubt, as well as its impact on victim participation, arrest, and referral for prosecution while controlling for relevant legal and extralegal factors. The findings suggest that officer doubt is an important consideration in sexual assault case processing, independent of other legal and extralegal factors, and that it significantly impacts the likelihood of arrest and referral for prosecution. Consistent with previous research, police decision-making was also impacted by certain legal factors. Victim participation was not directly affected by officer doubt but it was predicted by extralegal factors. Implications for future sexual assault research and practitioner training are discussed

Fatigue delamination onset prediction in tapered composite laminates

Tapered (0 deg) laminates of S2/CE9000 and S2/SP250 glass/epoxies, and IM6/1827I graphite/epoxy were tested in cyclic tension. The specimens usually showed some initial stable delaminations in the tapered region, but these did not affect the stiffness of the specimens, and loading was continued until the specimens either delaminated unstably, or reached 10(exp 6) to 2 x 10(exp 7) million cycles with no unstable delamination. The final unstable delamination originated at the junction of the thin and tapered regions. A finite-element model was developed for the tapered laminate with and without the initial stable delaminations observed in the tests. The analysis showed that for both cases the most likely place for an opening (Mode 1) delamination to originate is at the junction of the taper and thin regions. For each material type, the models were used to calculate the strain energy release rate, G, associated with delaminations originating at that junction and growing either into the thin region or tapered region. For the materials tested, cyclic G(sub Imax) values from DCB tests were used with the maximum strain energy release rates calculated from the finite-element analysis to predict the onset of unstable delamination at the junction as a function of fatigue cycles. The predictions were compared to experimental values of maximum cyclic load as a function of cycles to unstable delamination from fatigue tests in tapered laminates. For the IM6/1827I and S2/SP250 laminates, the predictions agreed very well with the test data. Predicted values for the S2/CE9000 were conservative compared to the test data

They Were There for People Who Needed Them : Student Attitudes Toward the Use of Trigger Warnings in Victimology Classrooms

Over the last five years, vigorous debate has been waged about the purpose, use, and impact of trigger warnings in courses offered at institutions of higher education. This debate has been largely uninformed by research findings. This study fills this gap using quantitative and qualitative data collected via surveys in a large undergraduate victimology course to explore student attitudes toward trigger warnings. Findings revealed considerable, but nuanced support for trigger warning use in victimology courses. Support does not appear to differ between crime victims and non-victims; support is higher among females than males. These findings underscore that universal decisions mandating or advocating for or against the use of trigger warnings are premature. Further study is needed with a diverse range of samples to gain a fuller picture of student attitudes about trigger warnings as well as to assess any impact of trigger warnings use on student behavior and learning