Seismic Design Coefficients for SpeedCore or Composite Plate Shear Walls - Concrete Filled (C-PSW/CF)

This report summarizes the results from FEMA P695 analytical studies conducted to verify the seismic design factors for composite plate shear walls – concrete filled (C-PSW/CF), also referred to as Speedcore. ASCE 7-16 provides the seismic design factors, which include the seismic response modification factor, R, deflection amplification factor, Cd, and overstrength factor, Ωo, for various approved seismic systems. C-PSW/CFs are assigned a response modification factor of 6.5, a deflection amplification factor of 5.5, and an overstrength factor of 2.5 for C-PSW/CFs. These seismic design factors were selected based on the seismic performance of similar structural systems and engineering judgment of the committee. This analytical study investigated and verified the appropriateness of these seismic design factors for walls with flange plates as boundary elements. Four planar (3-story, 6-story, 9-story, and 12-story) and three C-shaped (15-story, 18-story, and 22-story) C-PSW/CF walls were analyzed following the FEMA P695 procedure. This procedure included development of representative planar and C-shaped C-PSW/CF archetypes, calibration of numerical models for these archetypes, and evaluation of nonlinear static (pushover) and incremental dynamic (time history) analyses. The results indicate that seismic design coefficients of R = 6.5, Cd = 5.5, and Ωo = 2.5 appropriately quantify the seismic performance of C-PSW/CF with boundary elements. Walls without any boundary elements or closure plates are not recommended for seismic design based on supplementary analytical studies

Would Scots Law recognise a Dutch same-sex marriage?

Assesses the likelihood of Scottish law recognising the validity of same sex marriages performed in the Netherlands. Reviews case law concerning the recognition of foreign marriages per se, international private law's treatment of polygamous marriages and possible public policy arguments against same sex marriages. Explains the ways in which Scottish courts may give legal recognition to their consequences, including: (1) by acknowledging that they deny the parties the capacity to marry again for the duration of their subsistence, under the Marriage (Scotland) Act 1977 s.5(4); (2) by accepting the parties' entitlement to statutory protection in areas such as intestate succession or adoption; and (3) by the granting of matrimonial relief including divorce

Host preference by Saperda calcarata Say (Coleoptera: Cerambycidae)

We conducted five laboratory and one field experiments to examine potential host selection mechanisms of Saperda calcarata Say in British Columbia. Olfactory bioassays indicated that female (and possibly male) beetles were attracted to volatiles from leafy twigs of trembling aspen, Populus tremuloides Michaux. However, wounding of the bole, ethanol baiting, or both, did not result in significant orientation toward or attack of trembling aspens in the field. Feeding preferences for trembling aspen were strong for both sexes in choice bioassays, but in no-choice bioassays, females did not discriminate between trembling aspen and black cottonwood, P. trichocarpa Torrey & Gray. Scouler's willow, Salix scouleriana Barrat in Hooker, was fed upon the least by both sexes. When diameter of bolts offered as oviposition hosts was equalized, frequency of oviposition was similar among the three hosts. Our data suggest that feeding preference is the predominant mechanism of host selection by S. calcarata

Frictional sliding without geometrical reflection symmetry

The dynamics of frictional interfaces play an important role in many physical systems spanning a broad range of scales. It is well-known that frictional interfaces separating two dissimilar materials couple interfacial slip and normal stress variations, a coupling that has major implications on their stability, failure mechanism and rupture directionality. In contrast, interfaces separating identical materials are traditionally assumed not to feature such a coupling due to symmetry considerations. We show, combining theory and experiments, that interfaces which separate bodies made of macroscopically identical materials, but lack geometrical reflection symmetry, generically feature such a coupling. We discuss two applications of this novel feature. First, we show that it accounts for a distinct, and previously unexplained, experimentally observed weakening effect in frictional cracks. Second, we demonstrate that it can destabilize frictional sliding which is otherwise stable. The emerging framework is expected to find applications in a broad range of systems.Comment: 14 pages, 5 figures + Supplementary Material. Minor change in the title, extended analysis in the second par

Supersonic crack propagation in a class of lattice models of Mode III brittle fracture

We study a lattice model for mode III crack propagation in brittle materials in a stripe geometry at constant applied stretching. Stiffening of the material at large deformation produces supersonic crack propagation. For large stretching the propagation is guided by well developed soliton waves. For low stretching, the crack-tip velocity has a universal dependence on stretching that can be obtained using a simple geometrical argument.Comment: 4 pages, 3 figure

Velocity Fluctuations in Dynamical Fracture: the Role of Microcracks

We address the velocity fluctuations of fastly moving cracks in stressed materials. One possible mechanism for such fluctuations is the interaction of the main crack with micro cracks (irrespective whether these are existing material defects or they form during the crack evolution). We analyze carefully the dynamics (in 2 space dimensions) of one macro and one micro crack, and demonstrate that their interaction results in a {\em large} and {\em rapid} velocity fluctuation, in qualitative correspondence with typical velocity fluctuations observed in experiments. In developing the theory of the dynamical interaction we invoke an approximation that affords a reduction in mathematical complexity to a simple set of ordinary differential equations for the positions of the cracks tips; we propose that this kind of approximation has a range of usefulness that exceeds the present context.Comment: 7 pages, 7 figure

Self-Similar Law of Energy Release before Materials Fracture

A general law of energy release is derived for stressed heterogeneous materials, being valid from the starting moment of loading till the moment of materials fracture. This law is obtained by employing the extrapolation technique of the self-similar approximation theory. Experiments are accomplished measuring the energy release for industrial composite samples. The derived analytical law is confronted with these experimental data as well as with the known experimental data for other materials.Comment: Latex, 15 pages, no figure

Bone Status in Obese, Non-diabetic, Antipsychotic-Treated Patients, and Effects of the Glucagon-Like Peptide-1 Receptor Agonist Exenatide on Bone Turnover Markers and Bone Mineral Density

Background: Low bone mineral density (BMD) may constitute an underestimated comorbidity in schizophrenia patients undergoing long-term antipsychotic treatment. Glucagon-like peptide 1 (GLP-1) receptor agonists are antidiabetic drugs, which may also affect bone turnover.Methods: In planned secondary analyses of a 3 months, double-blind, randomized, placebo-controlled trial (n = 45), we explored effects of the GLP-1 receptor agonist exenatide 2 mg once-weekly (n = 23), or placebo (n = 22) on bone turnover markers (BTMs) and BMD in chronic, obese, antipsychotic-treated patients with schizophrenia spectrum disorder. Baseline BTMs were compared to sex- and age-adjusted reference values from a Danish population cohort, and T- and Z-scores were calculated for BMD.Results: In women (n = 24), all baseline BTM measurements of procollagen type I N-terminal propeptide (PINP) and C-terminal cross-linking telopeptide of type I collagen (CTX) were within reference values. In men (n = 21), 5% displayed lower PINP and 14% displayed lower CTX. One patient displayed BMD Z-score Conclusions: Sex- and age-adjusted measures of bone status in chronic, obese, antipsychotic-treated patients appeared comparable to the reference population. Subtle changes in bone markers during 3 months exenatide treatment may suggest beneficial effects of GLP-1 receptor agonists on bone status in antipsychotic-treated patients, and further studies should consider the potential influence of prolactin.</p

Analysis of the performance of a new concept for automatic draping of wide reinforcement fabrics with pre-shear:A virtual prototyping study

The layup process of large composite structures made from dry reinforcement fabrics is considered. One such structure is a wind turbine blade, for which the current draping process is mostly manual. Automating the draping process will, therefore, lower the costs. Based on a literature review, a new concept is synthesized and analyzed using an advanced finite element model with rigid multi-body kinematics and a dedicated material model for the fabric. The material model is calibrated using experimental coupon tests, i.e. the bias-extension test (shear) and Peirce's cantilever test (out-of-plane bending). The concept is analyzed numerically by means of a simple parameter study and draping test cases on a flat mold as well as a general double-curved mold. The simulation results show that the concept is feasible for the draping operation and is thus qualified for the subsequent physical prototyping.</p