scholarly journals STABILITAS PELAT ORTHOTROPIK AKIBAT BEBAN LEDAKAN FRIEDLANDER DAN BEBAN IN-PLANE

2021 ◽  
Vol 5 (2) ◽  
pp. 585
Author(s):  
Levina Lammirta ◽  
Sofia Wangsadinata Alisjahbana
Keyword(s):  
Critical Load ◽  
Dynamic Load ◽  
Compressive Load ◽  
Bending Moment ◽  
Blast Load ◽  
Positive Phase ◽  
Pasternak Foundation ◽  
Spring Coefficient ◽  
Foundation Parameters ◽  
Foundation Parameter

Slab behavior due to static and dynamic load needs to be considered when designing a slab. Friedlander is one of the examples of dynamic loads. This dynamic load can give different responses on slab. This research discusses about orthotropic plate on Pasternak foundation with fixed boundary condition and in-plane and Friedlander load. Three phases on Friedlander load are positive phase, negative phase, and free vibration phase. This research is conducted to find out critical buckling load due to variation of Pasternak foundation parameters which is spring coefficient and shear coefficient. The system responses are deflection and bending moment due to variation of Pasternak foundation parameter, critical loading, position of loads, depth of soil, and duration of positive phase.  Analysis is carried out using Modified Bolotin Method to obtain natural frequencies and mode shape of the system. Result of this research are displayed in graphics and tables. Based on the results, the maximum limit of the critical compressive load is 77% of the critical load used. The increasing of soil coefficient, the greater the deflection that occurs. The position of the load that is close to the center of the span will make the deflection even greater. The deflection that occurs is greater when the depth of the soil increases and the duration of the blast load is getting longer. The greater the thickness of the plate, the smaller the deflection. Keywords : Modified Bolotin Method, Friedlander blast load, plate deflection, critical load, Pasternak FoundationAbstrakPerilaku pelat akibat adanya beban statik dan beban dinamik perlu menjadi pertimbangan pada saat mendesain pelat. Salah satu contoh beban dinamik adalah beban ledakan setempat (Friedlander). Beban dinamik dapat memberikan respon yang beragam pada pelat. Penelitian ini membahas mengenai pelat orthotropik di atas pondasi Pasternak dengan kondisi jepit dengan beban in-plane dan beban ledakan setempat (Friedlander). Beban ledakan setempat (Friedlander) dianalisis dalam tiga fase yaitu fase positif, fase negatif, dan fase getaran bebas. Penelitian dilakukan untuk mengetahui beban tekuk kritis akibat variasi koefisien pondasi Pasternak yaitu koefisien pegas dan koefisien geser. Respons sistem yang diamati adalah lendutan dan momen yang dihasilkan akibat adanya variasi terhadap parameter pondasi Pasternak, besaran beban kritis, posisi beban, kedalaman tanah, dan durasi fase positif beban. Analisis dilakukan dengan Modified Bolotin Method untuk mendapatkan frekuensi alami dan ragam getar yang terjadi. Hasil analisis akan dibandingkan dalam bentuk grafik dan tabel. Berdasarkan hasil penelitian, batas maksimum beban tekan kritis adalah 77% dari beban kritis yang digunakan. Koefisien tanah yang semakin besar akan membuat lendutan yang terjadi semakin besar. Posisi beban yang mendekati tengah bentang akan membuat lendutan semakin besar. Lendutan yang terjadi semakin besar apabila kedalaman tanah semakin meningkat dan durasi beban ledakan yang semakin lama. Apabila semakin besar tebal pelat maka lendutan yang terjadi semakin kecil. 

scholarly journals PERILAKU DINAMIK PELAT PERKERASAN KAKU JALAN RAYA AKIBAT BEBAN LEDAKAN SETEMPAT

2020 ◽  
Vol 4 (2) ◽  
pp. 343
Author(s):  
Anjas Budi Priono ◽  
Sofia Wangsadinata Alisjahbana
Keyword(s):  
Free Vibration ◽  
Dynamic Response ◽  
Bending Moment ◽  
Blast Load ◽  
Positive Phase ◽  
Negative Phase ◽  
Concrete Slabs ◽  
Pasternak Foundation ◽  
Orthotropic Plates ◽  
Rigid Pavement

In structural and transportation engineering applications, the dynamic response of orthotropic plates is an essential matter. Rigid pavement plates are generally designed as orthotropic plates which have unequal stiffness in two perpendicular directions Engineers did not consider the effects of dynamic loads such as those from machine vibrations or blast load. Dynamic analysis of rigid pavement plates due to local blast loads on concrete slabs in this research is modeled as concrete slabs with boundary condition that every edges of plates have a dowel-tie bar support and The rigid concrete pavement sitting on elastics Pasternak foundation is modeled by using the Kirchhoff theory of thin plates. Pasternak foundation have elastic vertical spring support and continuous shear layer. The main system responses that are observed are the transversal deflections at midspan and the internal stresses of the plate, particularly the maximum principle stress, minimum principle stress and maximum shear stress. Three loading phases are included in the analysis, namely: the positive phase, the negative phase, and the free vibration phase. Analyses are carried out utilizing a numeric approach termed the Modified Bolotin Method with two trancedental equation. The analysis is performed when the load is above the plate (0 ≤ t ≤ t0). Deflection from various load positions on the set of slab models throughout all three phases are then compared side-by-side. Bending moment, shear forces, and stresses are calculated on all slab models with the Friedlander localized blast loading applied at midspan and the results are presented as stress contours that are then compared between each model. The results showed that the largest structural dynamic response occurred in the free vibration phase, not in the positive phase or the negative phase. Reduction of deflection and bending moment based on the most significant effect, plate thickness is the first followed by the effect of explosion position if it occurs further to edge of plate, and latest is adding supporting stiffness soil layer. Keywords: dowel and tie-bar; Localized blast load; Modified     Bolotin Method; Pasternak foundation; Rigid PavementABSTRAKDalam aplikasi rekayasa struktur dan teknik transportasi, respons dinamik pelat ortotropik adalah masalah penting. Pelat perkerasan kaku jalan raya umumnya didesain sebagai pelat ortotropik yang memiliki kekakuan yang tidak sama dalam dua arah yang saling tegak lurus. Pelat perkerasan kaku jalan raya sering kali didesain oleh para insinyur tidak memperhitungkan efek dari beban dinamik lain seperti beban yang berasal dari getaran mesin atau ledakan. Analisis dinamik pelat perkerasan kaku jalan raya akibat beban ledakan setempat di atas pelat beton dalam tesis ini dimodelkan sebagai pelat beton dengan kondisi semua tepi pelat beton memiliki tumpuan dowel – tie bar dan di atas media tanah dengan model pondasi Pasternak dari teori Kirchoff-Love mengenai pelat tipis. Pondasi Pasternak memiliki dukungan pegas vertikal elastis dan lapisan geser menerus di bawahnya. Respons sistem yang diamati adalah lendutan transversal pada tengah bentang dan tegangan dalam pada pelat, khususnya tegangan utama maksimum, tegangan utama minimum dan tegangan geser maksimum. Tiga tahap beban disertakan dalam analisis, yaitu fase positif, fase negatif dan fase getaran bebas. Analisis dikerjakan dengan pendekatan numerik yang disebut Modified Bolotin Method dengan bantuan dua persamaan transendental. Analisis dilakukan ketika beban berada di atas pelat (0 ≤ t ≤ t0). Lendutan dari beberapa posisi beban dari tiga tahap dibandingkan. Momen lentur, gaya geser, dan tegangan dihitungkan pada semua model dengan letak beban setempat Friedlander di tengah bentang. Nilai tegangan disajikan dalam bentuk grafik kontur yang dapat dibandingkan antara setiap model. Hasil penelitian menunjukkan respons dinamik struktur terbesar terjadi pada fase free vibration, bukan pada fase positif maupun fase negatif. Pengurangan lendutan dan momen lentur apabila ditinjau berdasarkan pengaruh paling singnifikan, ketebalan pelat adalah urutan pertama diikuti pengaruh posisi ledakan apabila terjadi makin ke tepi pelat, dan terakhir penambahan kekakuan lapisan tanah pendukung.

scholarly journals Dynamic Response of a Beam Subjected to Moving Load and Moving Mass Supported by Pasternak Foundation

2012 ◽  
Vol 19 (2) ◽  
pp. 205-220 ◽  
Author(s):  
Rajib Ul Alam Uzzal ◽  
Rama B. Bhat ◽  
Waiz Ahmed
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Dynamic Response ◽  
Moving Load ◽  
Bending Moment ◽  
Dynamic Responses ◽  
Moving Mass ◽  
Pasternak Foundation ◽  
Partial Differential ◽  
Foundation Parameters

This paper presents the dynamic response of an Euler- Bernoulli beam supported on two-parameter Pasternak foundation subjected to moving load as well as moving mass. Modal analysis along with Fourier transform technique is employed to find the analytical solution of the governing partial differential equation. Shape functions are assumed to convert the partial differential equation into a series of ordinary differential equations. The dynamic responses of the beam in terms of normalized deflection and bending moment have been investigated for different velocity ratios under moving load and moving mass conditions. The effect of moving load velocity on dynamic deflection and bending moment responses of the beam have been investigated. The effect of foundation parameters such as, stiffness and shear modulus on dynamic deflection and bending moment responses have also been investigated for both moving load and moving mass at constant speeds. Numerical results obtained from the study are presented and discussed.

scholarly journals Influence of the visco-Pasternak foundation parameters on the buckling behavior of a sandwich functional graded ceramic–metal plate in a hygrothermal environment

2022 ◽  
Vol 170 ◽  
pp. 108549
Author(s):  
Mohamad W. Zaitoun ◽  
Abdelbaki Chikh ◽  
Abdelouahed Tounsi ◽  
Mohammed A. Al-Osta ◽  
Alfarabi Sharif ◽  
...  
Keyword(s):  
Metal Plate ◽  
Pasternak Foundation ◽  
Buckling Behavior ◽  
Hygrothermal Environment ◽  
Foundation Parameters

Closed-form solution of beam on Pasternak foundation under inclined dynamic load

2017 ◽  
Vol 30 (6) ◽  
pp. 596-607 ◽  
Author(s):  
Yu Miao ◽  
Yang Shi ◽  
Guobo Wang ◽  
Yi Zhong
Keyword(s):  
Closed Form ◽  
Dynamic Load ◽  
Closed Form Solution ◽  
Form Solution ◽  
Pasternak Foundation

Large Amplitude Free Vibration of Shallow Spherical Shell on a Pasternak Foundation

1993 ◽  
Vol 115 (1) ◽  
pp. 70-74 ◽  
Author(s):  
D. N. Paliwal ◽  
V. Bhalla
Keyword(s):  
Free Vibration ◽  
Spherical Shell ◽  
Large Amplitude ◽  
Free Vibrations ◽  
Numerical Results ◽  
Shallow Spherical Shell ◽  
Pasternak Foundation ◽  
New Approach ◽  
Foundation Parameters ◽  
Clamped Edges

Large amplitude free vibrations of a clamped shallow spherical shell on a Pasternak foundation are studied using a new approach by Banerjee, Datta, and Sinharay. Numerical results are obtained for movable as well as immovable clamped edges. The effects of geometric, material, and foundation parameters on relation between nondimensional frequency and amplitude have been investigated and plotted.

Study on Dynamic Response of Hollow Pile Using the Method of Composite Stiffness Principle and Biparameter

2011 ◽  
Vol 243-249 ◽  
pp. 2679-2683
Author(s):  
Yong Mou Zhang ◽  
Min Yang ◽  
Qiang Gang Yan
Keyword(s):  
Dynamic Load ◽  
Bending Moment ◽  
Dynamic Loads ◽  
Concrete Pile ◽  
Side Resistance ◽  
Geological Conditions ◽  
Internal Forces ◽  
The Finite Difference Method ◽  
Composite Stiffness ◽  
Laterally Loaded

The method of composite stiffness principle and biparameter for laterally loaded pile was used in this paper to calculate the amplitude of deflection and rotation of pile on the ground when the vibration frequency of dynamic load is equal to or close to the natural frequency of pile, i.e. when the pile is in the state of resonance. And the amplitude of the maximum bending moment and its location was also calculated. Then the finite difference method which is simple in principle and easy to program was used to calculate the displacement, soil side resistance and internal forces of pile under horizontal dynamic load. By choosing reasonable parameters, rotation, displacement, and the maximum bending moment of hollow concrete pile and solid pile under the same dynamic loads at pile top in the same geological conditions were calculated respectively. On this basis, the performance differences between hollow pile and solid pile were analyzed. Some advantages of hollow pile were obtained. This research provides a theoretical guidance for the using of hollow pile in engineering.

Analytical Solution of Elastic-Plastic Buckling of a Square Steel Tube Column under Axial Compressive Load and Bending Moment

2010 ◽  
Vol 452-453 ◽  
pp. 485-488 ◽  
Author(s):  
Peng Niu ◽  
Gang Yang ◽  
Chun Fu Jin ◽  
Yi Xiong Wu
Keyword(s):  
Compressive Load ◽  
Bending Moment ◽  
Steel Tube ◽  
Plastic Buckling ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Axial Compressive Load ◽  
The Moment ◽  
Square Steel Tube ◽  
Analytical Expressions

Based on Ježek method of computing the elastic-plastic buckling of the member under the axial compressive load and the bending moment, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the moment of inertia for a square steel tube column are derived. By degenerated into the analytical expressions of the rectangular column and compared with the values of the finite element analysis (FEA) method, it shows that the analytical method in this paper is valid, which provides a new method of theoretical study for the elastic-plastic buckling of the member.

The Buckling of an Elastically Encastred Strut.

1936 ◽  
Vol 40 (311) ◽  
pp. 833-834 ◽  
Author(s):  
W. Prager
Keyword(s):  
Critical Load ◽  
Compressive Load ◽  
Neutral Axis ◽  
Bending Moments ◽  
Previous Issue ◽  
Total Length ◽  
Neutral Equilibrium ◽  
Ingenious Method

In a previous issue of this Journal (Vol. 40, pp.663-680, 1936) Mr. N. J. Hoff has investigated the buckling of an elastically encastred strut. The ingenious method used by Mr. Hoff consists in considering portions of various lengths of a rigidly encastred strut which is in a state of neutral equilibrium under the action of its critical compressive load. This load is also the critical load of an elastically encastred strut whose length is equal to the length of the considered portion, if only the rigidities of encastrement are chosen in accordance with the ratios of the slopes of the neutral axis at the ends of this portion to the bending moments there. The total length of the elastically encastred strut does not enter immediately into the formulae derived by this method, there enter only two lengths x1 and xr whose sum is equal to the total length. These quantities are the distances between the ends of the considered portion of the rigidly encastred strut and the middle of its span.

Delamination Cracking in Thermal Barrier Coating System

2002 ◽  
Vol 124 (4) ◽  
pp. 922-930 ◽  
Author(s):  
Y. C. Zhou ◽  
T. Hashida
Keyword(s):  
Thermal Stress ◽  
Temperature Gradient ◽  
Thermal Barrier Coating ◽  
Ceramic Coating ◽  
Compressive Load ◽  
Bending Moment ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Thermal Growth ◽  
Coating Delamination

Delamination cracking in thermal barrier coating (TBC) system is studied with the newly developed theoretical model. A semi-infinite long interface crack is pre-existing. The thermal stress and temperature gradient in TBC system are designated by a membrane stress P and a bending moment M. In this case, the effects of plastic deformation, creep of ceramic coating, as well as thermal growth oxidation and temperature gradient in TBC system are considered in the model due to the fact that these effects are considered in the calculation of thermal stress. The energy release rate, mode I and mode II stress intensity factors, as well as mode mixed measure ψ, are derived. The emphatic discussion about PSZ/Ni-alloy reveals that the TBC system may not fail in the form of coating delamination during the period of heat hold. However, the failure may be in the form of coating delamination during cooling or in the heating period during the second cycle or later cycles. The conclusion is consistent with the experimental observations. The delamination of ceramic coating is induced by the compressive load in the coating.

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