scholarly journals Explicit Dynamic Analysis by a Rigid Body-Spring Model of Impact Loads of Artillery on Middle Age Fortifications

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 607
Author(s):  
Vito Tateo ◽  
Siro Casolo
Keyword(s):  
Rigid Body ◽  
Middle Ages ◽  
Architectural Design ◽  
Inner Core ◽  
Middle Age ◽  
Numerical Models ◽  
Impact Loads ◽  
Spring Model ◽  
Explicit Dynamic ◽  
The Impact

The development of artillery in Europe at the end of the Middle Ages brought a necessary change in military architecture. This change was a radical rethinking of the entire geometry and architectural design of city walls which required an increase in thickness to resist repeated artillery strikes. The damage due to the impact loads on Middle Age fortification walls is analyzed herein with explicit dynamic analyses. This study was developed both with finite element models and an innovative rigid body-spring model with diagonal springs (RBSM), showing the different peculiarities of these two different approaches and how their results can be integrated. The numerical models clearly showed that the presence of an inner core of softer material tends to modify the impact effects by reducing the degree of damage at the expense of an extension of the damaged area.

scholarly journals A cross-sectional study on interference control: age affects reactive control but not proactive control

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8365 ◽  
Author(s):  
Yanfang Peng ◽  
Qin Zhu ◽  
Biye Wang ◽  
Jie Ren
Keyword(s):  
Middle Ages ◽  
Middle Age ◽  
The Elderly ◽  
Efficiency Score ◽  
Interference Control ◽  
Reactive Control ◽  
Cross Sectional ◽  
Age Related ◽  
The Difference ◽  
The Impact

Background Working memory updating (WMU), a controlled process to continuously adapt to the changing task demand and environment, is crucial for cognitive executive function. Although previous studies have shown that the elderly were more susceptible to cognitive interference than the youngsters, the picture of age-related deterioration of WMU is incomplete due to lack of study on people at their middle ages. Thus, the present study investigated the impact of age on the WMU among adults by a cross-sectional design to verify whether inefficiency interference control accounts for the aging of WMU. Methods In total, 112 healthy adults were recruited for this study; 28 old adults (21 female) ranging from 60 to 78 years of age; 28 middle-age adults (25 female) ranging from 45 to 59 years of age; 28 adults (11 female) ranging from 26 to 44 years of age; and 28 young adults (26 female) ranging from 18 to 25 years of age. Each participant completed a 1-back task. The inverse efficiency score was calculated in various sequences of three trials in a row to quantify the performance of WMU for adults of various ages. Results Inverse efficiency score of both young groups (young adult and adult) were significantly shorter than the old group in both Repeat-Alternate (RA, including □□○ and ○○□) and Alternate-Alternate (AA, including ○□○ and □○□) sequential patterns and they were additionally better than the middle-age group in AA sequential pattern. Conclusion With the increase of difficulty in the task, the difference in reactive interference control between young and middle age was gradually revealed, while the difference between young and old remained to apparent. The degradation of WMU aging may begin from middle-age and presents selective impairment in that only reactive interference control, but not proactive interference control, shows pronounced age-related decline. The preliminary results can inform future studies to further explore the whole lifespan trajectories of cognitive functions.

scholarly journals Experimental and FE Study on Impact Strength of Toughened Glass–Retrospective Approach

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7658
Author(s):  
Marcin Kozłowski ◽  
Kinga Zemła ◽  
Magda Kosmal ◽  
Ołeksij Kopyłow
Keyword(s):  
Numerical Models ◽  
Peak Stress ◽  
Impact Loads ◽  
Toughened Glass ◽  
Load Duration ◽  
Wide Range ◽  
Modelling Methodology ◽  
Glass Panels ◽  
Set Up ◽  
The Impact

Due to the high cost of experiments commonly performed to verify the resistance of glass elements to impact loads, numerical models are used as an alternative to physical testing. In these, accurate material parameters are crucial for a realistic prediction of the behaviour of glass panels subjected to impact loads. This applies in particular to the glass’s strength, which is strictly dependent on the strain rate. The article reports the results of an extensive experimental campaign, in which 185 simply supported toughened glass samples were subjected to hard-body impacts. The study covers a wide range of glass thicknesses (from 5 to 15 mm), and it aims to determine a critical drop height causing fracture of the glass. Moreover, a 3D numerical model of the experimental set-up was developed to reproduce the experiments numerically and retrospectively to determine the peak stress in glass that developed during the impact. Based on the results of numerical simulations, a load duration factor of 1.40 for toughened glass for impact loads is proposed. In addition, the paper includes a case study to demonstrate the use of the modelling methodology and results of the work on a practical example of an internal glass partition wall.

scholarly journals The Impact of High-Frequency/ Low-Energy Seismic Waves on Unreinforced Masonry

2007 ◽  
Vol 23 (1) ◽  
pp. 77-94 ◽  
Author(s):  
Patrik Meyer ◽  
John Ochsendorf ◽  
John Germaine ◽  
Eduardo Kausel
Keyword(s):  
High Frequency ◽  
Structural Damage ◽  
Seismic Waves ◽  
Inner Core ◽  
Energy Content ◽  
Numerical Models ◽  
Unreinforced Masonry ◽  
Low Energy ◽  
Masonry Structures ◽  
The Impact

Traditionally, the high-frequency components of earthquake loading are disregarded as a source of structural damage because their energy content is small and their frequency is too high to resonate with the natural frequencies of structures. We argue that higher-frequency waves traveling through stiff masonry structures can trigger two types of failure mechanisms that have not yet been taken into account. First, the high frequencies can cause small vertical interstone vibrations that result in irreversible relative displacements of the stones, which may ultimately lead to collapse. The energy needed to cause this deformation and failure comes largely from gravitational forces. Second, the partial fluidification and densification of the loose, granular inner core of some unreinforced masonry walls results in an increase of outward thrust. Preliminary results of a series of static and dynamic tests, as well as numerical models, demonstrate the potentially destructive effects of high-frequency/low-energy seismic waves on unreinforced masonry structures. Based on this new understanding, an improved construction method is suggested.

scholarly journals Frequency of Dental Caries in Four Historical Populations from the Chalcolithic to the Middle Ages

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
A.-M. Grimoud ◽  
S. Lucas ◽  
A. Sevin ◽  
P. Georges ◽  
O. Passarrius ◽  
...  
Keyword(s):  
Middle Ages ◽  
Food Access ◽  
Middle Age ◽  
Population Sample ◽  
Historical Period ◽  
South West ◽  
Time Period ◽  
Carious Lesions ◽  
The Impact

The majority of dental carie studies over the course of historical period underline mainly the prevalence evolution, the role of carbohydrates consumption and the impact of access to dietary resources. The purpose of the present investigation was to compare population samples from two archaeological periods the Chacolithic and Middle Age taking into account the geographical and socio economical situation. The study concerned four archaelogical sites in south west France and population samples an inlander for the Chalcolithic Age, an inlander, an costal and urban for the Middle Age. The materials studied included a total of 127 maxillaries, 103 mandibles and 3316 teeth. Data recorded allowed us to display that the Chalcolithic population sample had the lowest carie percentage and the rural inlander population samples of Middle Age the highest; in all cases molars were teeth most often affected. These ones differences could be explained according to time period, carious lesions were usually less recorded in the Chalcolithic Age than the Middle because of a lesser cultivation of cereals like in les Treilles Chacolithic population sample. In the Middle Age population samples, the rural inland sample Marsan showed the highest frequency of caries and ate more cereal than the coastal Vilarnau and the poor urban St Michel population samples, the first one ate fish and Mediterranean vegetal and fruits and the second one met difficulties to food access, in both cases the consumption of carbohydrates was lesser than Marsan population sample who lived in a geographical land convice to cereals cultivation.

scholarly journals A Rational Numerical Method for Simulation of Drop-Impact Dynamics of Oleo-Pneumatic Landing Gear

2021 ◽  
Vol 11 (9) ◽  
pp. 4136
Author(s):  
Rosario Pecora
Keyword(s):  
Numerical Method ◽  
Initial Conditions ◽  
Impact Load ◽  
Numerical Models ◽  
Landing Gear ◽  
Design Stage ◽  
Impact Dynamics ◽  
State Variables ◽  
Adopted Model ◽  
The Impact

Oleo-pneumatic landing gear is a complex mechanical system conceived to efficiently absorb and dissipate an aircraft’s kinetic energy at touchdown, thus reducing the impact load and acceleration transmitted to the airframe. Due to its significant influence on ground loads, this system is generally designed in parallel with the main structural components of the aircraft, such as the fuselage and wings. Robust numerical models for simulating landing gear impact dynamics are essential from the preliminary design stage in order to properly assess aircraft configuration and structural arrangements. Finite element (FE) analysis is a viable solution for supporting the design. However, regarding the oleo-pneumatic struts, FE-based simulation may become unpractical, since detailed models are required to obtain reliable results. Moreover, FE models could not be very versatile for accommodating the many design updates that usually occur at the beginning of the landing gear project or during the layout optimization process. In this work, a numerical method for simulating oleo-pneumatic landing gear drop dynamics is presented. To effectively support both the preliminary and advanced design of landing gear units, the proposed simulation approach rationally balances the level of sophistication of the adopted model with the need for accurate results. Although based on a formulation assuming only four state variables for the description of landing gear dynamics, the approach successfully accounts for all the relevant forces that arise during the drop and their influence on landing gear motion. A set of intercommunicating routines was implemented in MATLAB® environment to integrate the dynamic impact equations, starting from user-defined initial conditions and general parameters related to the geometric and structural configuration of the landing gear. The tool was then used to simulate a drop test of a reference landing gear, and the obtained results were successfully validated against available experimental data.

Lighting energy performance determination in office environments through implementation of EN 15193-1 for Turkey

2021 ◽  
pp. 147715352098742
Author(s):  
FŞ Yilmaz
Keyword(s):  
System Design ◽  
Architectural Design ◽  
Office Buildings ◽  
Energy Requirements ◽  
System Control ◽  
Lighting System ◽  
Artificial Lighting ◽  
Design Alternatives ◽  
Lighting Energy ◽  
The Impact

Office buildings are building typologies where efficient and optimal use of lighting energy is crucial while providing comfortable visual environments. The purpose of this study is to explore the impact of diverse architectural design alternatives on lighting energy requirements and lighting energy saving possibilities through a case study. In this study, a total of 3888 design alternatives are investigated in a comparative way in terms of daylighting system design alternatives, artificial lighting system design scenarios, artificial lighting system control types and shading system control options. Introducing the adaptation process of the EN 15193-1:2017 standard for Turkey’s specific climatic and geographical conditions and considering diverse lighting design scenarios, results of this parametric study aim to underline the significance of architectural design strategies in office buildings for the reduction of lighting energy requirements.

scholarly journals Evidence-Based Design in Architectural Education: Designing the First Maggie’s Centre in Israel

2021 ◽  
pp. 193758672110079
Author(s):  
Nirit Putievsky Pilosof ◽  
Yasha Jacob Grobman
Keyword(s):  
Literature Review ◽  
Architectural Design ◽  
Early Stage ◽  
Scientific Research ◽  
Well Being ◽  
Architectural Education ◽  
Local Context ◽  
Evidence Based ◽  
Architecture Education ◽  
The Impact

Objective The study examines the integration of the Evidence-based Design (EBD) approach in healthcare architecture education in the context of an academic design studio. Background Previous research addressed the gap between scientific research and architectural practice and the lack of research on the use of the EBD approach in architectural education. Methods The research examines an undergraduate architectural studio to design a Maggie’s Centre for cancer care in Israel and evaluates the impact of the EBD approach on the design process and design outcomes. The research investigates the impact of the integration of three predesign tasks: (1) literature review of healing architecture research, (2) analysis and comparison of existing Maggie’s Centres, and (3) analysis of the context of the design project. Results The literature review of scientific research supported the conceptual design and development of the projects. The analysis of existing Maggie’s centers, which demonstrated the interpretation of the evidence by different architects, developed the students’ ability to evaluate EBD in practice critically, and the study of the projects’ local context led the students to define the relevance of the evidence to support their vision for the project. Conclusions The research demonstrates the advantages of practicing EBD at an early stage in healthcare architectural education to enhance awareness of the impact of architectural design on the users’ health and well-being and the potential to support creativity and innovative design. More studies in design studios are needed to assess the full impact of integrating EBD in architectural education.

Assessment of the impact of gaseous ship emissions in ports using physical and numerical models: The case of Naples

2021 ◽  
pp. 107812
Author(s):  
Domenico Toscano ◽  
Massimo Marro ◽  
Benedetto Mele ◽  
Fabio Murena ◽  
Pietro Salizzoni
Keyword(s):  
Numerical Models ◽  
Ship Emissions ◽  
The Impact
Sign in / Sign up

Export Citation Format

Share Document