Analysis of different cross-frame placements to enhance torsional irregular buildings against structural failure under earthquake bidirectional loadings: A case study

Cross bracing frames (CFs) are employed as traditional passive energy dissipating devices, which are placed into the moment-resisting frames of the Benchmark building picked for analysis purposes. These devices are widely used, easy to construct, and inexpensive to contribute better seismic protection for existing and new buildings as compared to complex control systems like active/passive Tuned Mass Dampers (TMDs) and so on. Therefore, in this research, the best three-predetermined CFs placements are selected, and the time history analyses are made under bi-directional seismic loads such as two orthogonal excitations of El Centro in 1940, North-Ridge in 1994, and Kocaeli, Turkey in 1999. In conclusion, the obtained results show that integrating CFs into MRFs should be made by taking into consideration eliminating eccentricity in the seismic design; otherwise, they can lead to an increase in the possibility of structural damages.Çapraz Destek Profilleri (ÇDP), günümüzde özellikle eksantrik binaları deprem esnasında burulmaya karsı korumak için kullanılan yöntemlerden biridir. Bu yöntem, aktif / pasif Ayarlı Kütle Damperleri (AKD) gibi karmaşık kontrol sistemlerine kıyasla, mevcut ve yeni binalar için daha iyi bir sismik korumaya katkıda bulunmak için yaygın olarak kullanılır. Çünkü yapımı kolaydır ve uygulaması diğer yöntemlere göre daha ucuzdur. Bu nedenle, bu araştırmada, önceden belirlenmiş en iyi üç ÇDP yerleşimleri seçilerek, iki yönlü sismik yükler altında sismik analizleri, 1940'da El Centro, 1994'te North-Ridge ve Kocaeli 1999 deprem dataları altında yapılmıştır. Elde edilen sonuçlara göre ÇDP'ler yapıya yerleştirilirken Durum 3’teki gibi doğru bir mühendislik tasarım perspektifi ile birlikte yapıda burulma tepkilerini (yaklaşık olarak %30 ile %50 arasında) azaltarak yapı planındaki eksantrikliği önemli ölçüde ortadan kaldırabilirken, doğru tasarım vizyonu ile yerleştirilmeyen ÇDP'ler yani Durum 1 ve Durum 2’da olduğu gibi burulma etkilerini bazı yükleme durumları için azaltacak kadar başarılı olamamışlardır. Bu nedenle, yapısal tepkileri en aza indirmek için ÇDP’leri yapıya entegre etmek, doğru mühendislik perspektifi ile yapılmalıdır. Aksi takdirde ÇDP’ler yapıdaki burulma düzensizliği etkilerini azaltmadığı gibi binada burulmadan dolayı oluşabilecek yapısal hasar olasılığının da artmasına neden olabilmektedir

Kinematic Analyses of Metallic Plate Perforation by Penetrators with Various Nose Geometries

This study analyses kinematics of a metallic plate perforation by a penetrator with truncated ogive nose geometry to find solutions also to blunt, conical, ogive, and hemi-spherical nosed penetrators. Plugging, ductile hole enlargement, dishing, and petal forming failure modes are used in the analyses. Acceleration throughout perforation is calculated by using the related failure mode, analytical model, and the target-penetrator interaction geometry. Depending on the failure model; back lip and front lip formation during ductile hole enlargement, plug formation during plugging, and deflection of target plate during dishing is also analysed. Analyses are based on projectile’s equation of motion, momentum and energy equations, and projectile-target plate interactions. The analyses results for selected cases, with the impact velocity range 215-863 m/s, are compared with the test data. The residual velocity estimation for a strike velocity is close to the related test data with an error of 0.3-2.2 %, except for conical nosed penetrators at impact velocities approaching the ballistic limit velocit

Our disappearing values; art of natural dyeing

Turizm pazarında, doğaya dayalı turizm olarak tarif edilen kırsal turizm, sürdürülebilir kalkınma aracı olarak görülmektedir. Karaman il sınırları içinde önceleri çok önemli kültür miraslarımızdan olan halı-kilim dokumacılığının yapıldığı ve halen yer yer dokumanın devam ettiği merkezlerinden Taşkale (halı), Ayrancı Büyükkoraş-Küçükkoraş-Çat (halı)-Berendi (kilim, halı) Köyleri ile Kazımkarabekir ilçesi (kilim) kayda değer yerlerdir. Kültürel sanatlarından olan el halısı ve kilimi yapımında kullanılan iplerin doğal boyama ile hazırlanması kaybolan değerlerimizdendir. Karaman ili coğrafi konumu gereği birçok iklim karakterlerini taşıyan ender yerlerden biridir. Bundan dolayıdır ki, bizim de doğal boyamada kullandığımız birçok bitkinin yetişme yeridir. Doğal boyamacılığın temel bitkilerinden olan; kırmızı rengin ana kaynağı Rubia tinctorum L. Kılbasan Tilki Tepesi mevkiinde “boyalık “ denilen yerde, sarı renkte kullanılan Rhamnus tinctoria L. Pınarbaşı Köyü civarında, Vitis vinifera L., kahverengi renkte kullanılan Juglon regia L., gri,siyah tonlarında kullanılan Punica granatum L. kültüre de alınan boya bitkileridir. Bunların yanında sarı rengin alternatif bitkilerinden olan Antehemis tinctoria L., Verbascum sp. , Berberis sp., Hypericium sp., Salvia sp,… il sınırlarında potansiyel olabilecek seviyededir.In the tourism market, the nature-based tourism is described as rural tourism which seen as sustainable development tool. Formerly in the province of Karaman carries very important cultural heritages which are carpet and kilim weaving. The weaving is still continues in remarkable places at Karaman districts which are Taşkale centers (carpets), Ayrancı Büyükkoraş-Küçükkoraş-Çat (carpets)-Berendi (kilims and carpets) and Kazımkarabekir (kilims). Culturally natural dyeing lines used in handmade carpets and kilims which are our disappearing values. Geographical location of Karaman province is one of the rare places with different climate characters because of that Karaman also is a natural habitat of many plants used in natural dyeing. Basic plants of natural dyeing are; the main source of red color Rubia tinctorum L. in Tilki Hill location, Kılbasan district which is named “boyalik (dyeing place) “, yellow color Rhamnus tinctoria L. in Pınarbaşı, yellow color Vitis vinifera L., and brown color Juglon regia L., gray, black and shade colors used in the Punica granatum L. in Karaman province. In addition to these plants, there are an alternative plants to give yellow color from Antehemis tinctoria L., Verbascum sp. , Berberis sp., Hypericium sp., Salvia sp ... which are grown in Karaman province

Lateral and torsional seismic vibration control for torsionally irregular buildings

During strong earthquakes or wind gusts, it is likely that buildings with torsional irregularity in the plan can be seriously damaged, partially collapsed or fully collapsed. This is because Torsionally Irregular Buildings (TIBs) may have significant aerodynamic torsion loads that increase the eccentricity between the center of mass and the center of rigidity, especially in dominant torsion modes. For this reason, torsion leads to excessive increase in lateral motions when dynamic loads excite the buildings. Torsional irregularity is one of the main failure causes during strong dynamic excitations due to earthquakes or wind gusts. Ignoring torsional irregularity in seismic design analysis can cause unexpected damages and losses. To enhance the safety and performance of buildings, most of the current seismic provisions address this irregularity in two main ways. The first is computing torsional moment at each floor by using equations provided in various current seismic code provisions. After they are applied on each floor, the seismic analysis will be performed. The second is shifting the center of mass (CM) or stiffness (CS) to eliminate the eccentricity by putting additional masses or structural components such as braced frame systems on buildings. This research developed and validated a new torsionally effective control system for the purpose of enhancing the performance/safety and mitigating structural failure in Torsionally Irregular Buildings (TIBs) under bidirectional strong earthquake loads. It introduces the new integrated control system (ICS) applied to a benchmark 9-story steel building developed for the SAC project in California to suppress the undesirable lateral and torsional coupling effects due to eccentricity. The dynamic responses of the system were evaluated under N-S and W-E components of the real earthquake excitations of the El Centro (1940), Loma Prieta (1989) and Kocaeli (1999) earthquakes. First the traditional method (cross-braced frame systems) was implemented in the benchmark building with different pre-determined placement layouts. The most effective placement was determined and the benchmark building was analyzed with that for comparison purpose. Secondly, tuned mass dampers (TMDs) were designed and applied to start from the center of mass (CM) through two translational directions under bi-directional seismic loads such as N-S and E-W components of selected ground motions. Then the performance evaluation for TMDs was determined. The effectiveness of the TMD system was evaluated in terms of energy analyses and performance evaluation criteria including maximum floor displacement, maximum drift, and maximum floor acceleration. Based on these comparisons, there is a substantial reduction of the amplitudes of the frequency response validated the effectiveness of the ICS in controlling the seismic responses for two-way eccentric elastic buildings. Unlike traditional TMDs placed in two orthogonal directions, the ICS is more comprehended to control not only two orthogonal (x- and y-) directions, but also effectively control rotational (θ-) direction. By means of the proposed system configuration, the structures first-three dominants modes can effectively be controlled by the ICS regardless of any external energy sources. The ICS is also more robust in restricting the inter-story drift ratio as compared with TMDs. It sufficiently mitigates the RMS and peak displacement on the top floor of the Benchmark building. Thus, the ICS has a better performance than the TMDs and the CFs placement in terms of response reductions. According to the performance evaluation criteria, there are substantial reductions for both the tuning case and the detuning case. For both cases, the performance indexes are overall less than the bare Benchmark building and its respective application with the TMDs. FOR FULL-TEXT READ, PLEASE CLICK ON THE LINK BELOW https://repository.lib.fit.edu/handle/11141/280

Remote-controlled ambidextrous robot hand actuated by pneumatic muscles: from feasibility study to design and control algorithms

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University LondonThis thesis relates to the development of the Ambidextrous Robot Hand engineered in Brunel University. Assigned to a robotic hand, the ambidextrous feature means that two different behaviours are accessible from a single robot hand, because of its fingers architecture which permits them to bend in both ways. On one hand, the robotic device can therefore behave as a right hand whereas, on another hand, it can behave as a left hand. The main contribution of this project is its ambidextrous feature, totally unique in robotics area. Moreover, the Ambidextrous Robot Hand is actuated by pneumatic artificial muscles (PAMs), which are not commonly used to drive robot hands. The type of the actuators consequently adds more originality to the project. The primary challenge is to reach an ambidextrous behaviour using PAMs designed to actuate non-ambidextrous robot hands. Thus, a feasibility study is carried out for this purpose. Investigating a number of mechanical possibilities, an ambidextrous design is reached with features almost identical for its right and left sides. A testbench is thereafter designed to investigate this possibility even further to design ambidextrous fingers using 3D printing and an asymmetrical tendons routing engineered to reduce the number of actuators. The Ambidextrous Robot Hand is connected to a remote control interface accessible from its website, which provides video streaming as feedback, to be eventually used as an online rehabilitation device. The secondary main challenge is to implement control algorithms on a robot hand with a range twice larger than others, with an asymmetrical tendons routing and actuated by nonlinear actuators. A number of control algorithms are therefore investigated to interact with the angular displacement of the fingers and the grasping abilities of the hand. Several solutions are found out, notably the implementations of a phasing plane switch control and a sliding-mode control, both specific to the architecture of the Ambidextrous Robot Hand. The implementation of these two algorithms on a robotic hand actuated by PAMs is almost as innovative as the ambidextrous design of the mechanical structure itself

Vibration control by active integrated control system under bidirectional ground motions

To improve the safety and security of the structures with irregular plan configuration, the new torsionally effective passive control system (ICS) was first proposed by the author, which utilizes a new design configuration to dissipate the unwanted energy from the structures in the lateral and torsional directions. In this research, a new active structural control approach, which is the active form of the ICS (or active integrated control system, AICS), is introduced as an alternative active control system, especially for the buildings with torsional sensitivity. In the design of active system configurations, two actuators driven by the linear quadratic regulator (LQR) are implemented and used to apply the optimum control forces to the ATMDs and AICS. For examining the performance of the proposed system configuration, the final design is applied to the 9-story Benchmark steel structure subjected to bidirectional three historical earthquakes. The obtained results show the overall performance of structural performance by using the AICS is substantially improved as compared to conventional ones (ATMDs) under selected ground accelerations with a 3% to 6% improvement in the lateral directions and by nearly 20% in the torsional direction in terms of the peak and root mean square response reduction

EVALUATION OF BREAD WHEAT GENOTYPES WITH DIFFERENT PHENOLOGICAL CHARACTERS IN TERMS OF RESISTANCE TO SUNN PEST DAMAGE

The research was conducted with 23 different varieties in field condition and closed area in 2010 and 2011. Twenty three bread wheat varieties were grown in open fields and closed areas in Faculty of Agriculture, University of Namik Kemal experimental area. The nifm number, sunn pest damage ratio, black point, protein ratio, moisture ratio, sedimentation rate, retarded sedimentation rate, gluten rate and index in the bread wheat varieties were examined. The highest sunn pest damage rate in the samples grown in field condition was found from Tekirdağ sample with 3,08 % and followed by Alga, Renan, Sadova, Geya and Krasnodarskaya-99 samples. The lowest damage rate was obtained from Enola and Dropia with 1,60 %; Krasunia with 1,63 %. In bread wheat samples grown in closed areas, the sunn pest damage rate increased considerably and measured between 4,93-12,75%. According to the average of two seasons, the highest sunn pest damage rate was obtained respectively from Geya, Tekirdağ, Renan and Sadova samples. The lowest damage rates were obtained from Gelibolu, KateA-1, Krasunia and Dropia samples. When the quality features were analysed, gluten, gluten index, zeleny sedimentation and retarded sedimentation values reduced substantially in comparison with values obtained outdoors. Retarded sedimentation values in all samples were at a quite low level that making the crop useless