Three-Dimensional Macro-Modeling of Concrete Slabs Subjected to Missile Impact Loading

This article is aimed to reveal the dynamic response of layered graded metallic foam under impact loading using a three-dimensional mesoscopic model. First, a mesoscopic model for closed-cell metallic foam is proposed based on the X-ray computed tomography images. Second, a numerical analysis approach is presented and validated with test data. Third, it studies the dynamic behavior of the layered graded metallic foam under impact loading numerically. The metallic foam specimen is composed layer by layer. The porosity, which is a fraction of the voids volume over the total volume, is different with each other for the layers. Simulations are conducted to the specimen with increasing and decreasing porosity arrangement. Results show that the layer arrangement is critical to the dynamic properties. The mesoscopic deformation of cell walls and the energy absorption capability are also affected significantly. This article gives insights into the mechanical properties and mesoscopic deformation of layered graded metallic foam.

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Numerical Simulation of Impact Response Behavior of Rectangular Reinforced Concrete Slabs under Falling-Weight Impact Loading

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.82.266 ◽

2011 ◽

Vol 82 ◽

pp. 266-271 ◽

Cited By ~ 7

Author(s):

Norimitsu Kishi ◽

Yusuke Kurihashi ◽

Sara Ghadimi Khasraghy ◽

Hiroshi Mikami

Keyword(s):

Reinforced Concrete ◽

Numerical Analysis ◽

Impact Loading ◽

Dynamic Responses ◽

Concrete Slabs ◽

Analysis Method ◽

Numerical Analysis Method ◽

Reinforced Concrete Slabs ◽

Weight Impact ◽

Falling Weight

A numerical analysis method for rectangular reinforced concrete slabs under falling-weight impact loading is established. The proposed method using ﬁnite element analysis incor-porates a simple constitutive model for concrete elements. The applicability was investigatedcomparing the numerical results with the experimental data. Falling-weight impact tests wereconducted on reinforced concrete slabs with diﬀerent supporting conditions. These were: a slabwith line supports on four sides; a slab with two line supports on two opposite sides (the othertwo sides were free); and a slab with one line and two corner-point supports. Following resultswere obtained from this study: (1) the time histories of dynamic responses are well predictedby using proposed numerical analysis method; (2) maximum reaction forces and the maximumdeﬂections in the slab center below the loading point, and characteristics of the damped freevibration after falling weight was rebounded, can be better predicted; and (3) major crackpatterns can be roughly predicted despite of support conditions.

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A half plane crack under three-dimensional combined mode impact loading

Acta Mechanica Sinica ◽

10.1007/bf02487656 ◽

1994 ◽

Vol 10 (1) ◽

pp. 40-48 ◽

Cited By ~ 3

Author(s):

Liu Chuntu ◽

Li Xiangping

Keyword(s):

Half Plane ◽

Impact Loading ◽

Three Dimensional ◽

Plane Crack ◽

Combined Mode

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THE EFFECT OF IMPACT LOADS ON PRESTRESSED CONCRETE SLABS

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2018.54 ◽

2018 ◽

Vol 5 (1) ◽

Author(s):

Youmn Al Rawi ◽

Yehya Temsah ◽

Hassan Ghanem ◽

Ali Jahami ◽

Mohamad Elani

Keyword(s):

Reinforced Concrete ◽

Prestressed Concrete ◽

Impact Loading ◽

Concrete Slab ◽

Concrete Slabs ◽

Shear Mode ◽

Reinforced Concrete Slab ◽

Finite Element Program ◽

Reinforced Concrete Slabs ◽

The Impact

Many research studies have been conducted on the effect of impact loading on structures, and design procedures were proposed for reinforced concrete (RC) slabs; however the availability of these studies and procedures are limited for prestressed slabs. The proposed research will examine, using numerical analysis, the impact of rock fall on prestressed concrete slabs with equivalent moment capacity reinforced concrete slabs. It is expected that prestressed concrete slabs will have different behavior to resist impact loading compared with traditional reinforced concrete slabs. The thickness of the prestressed concrete slab will be 25cm whereas that of the reinforced concrete slab will be 30cm. The impact loading consists of 500Kg drop weight. The drop height will be 10m, 15m and 20m.The structural analysis is performed using a Finite Element program "ABAQUS". A comparison will be done between both slab types in terms of failure mode, damage, and deflection. It has been found that both slabs failed in punching. However, the RC slab performed better than the prestressed concrete slab with respect to the value of the deflection at mid-span, while both showed punching shear mode of failure.

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BEHAVIOR OF REINFORCED CONCRETE SLABS UNDER ACCIDENTAL IMPACTS

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2018.73 ◽

2018 ◽

Vol 5 (2) ◽

Author(s):

Shamsoon Fareed

Keyword(s):

Reinforced Concrete ◽

Impact Loading ◽

Concrete Slab ◽

High Mass ◽

Concrete Slabs ◽

Reinforced Concrete Slab ◽

Reinforced Concrete Slabs ◽

Numerical Predictions ◽

Operational Life ◽

The Impact

Loads resulting from activities such as rock fall, heavy drop weights (for e.g. equipment's, heavy machines during installation), missile and aircraft interaction with slabs may results in loading intensity which have higher magnitude as compared to static loading. Based on the velocity of the impacting object at the time of contact, these activities may result in impact loading. Therefore, slabs designed should provide resistance to these accidental loading during their entire operational life. In this study, a dynamic non-linear finite element analyses were conducted to investigate the behavior of the reinforced concrete slabs subjected to high-mass low-velocity impacts. For this purpose, initially an already published impact test results were used to validate the numerical predictions. Following validation, a study was conducted to investigate the influence of the impact velocity on the behavior of the reinforced concrete slab. Based on the numerical investigation, it was found that the velocity of the impacting object has a significant influence on the behavior exhibited by slab under impact loading. Furthermore, it was also found that the behavior of slab under impact is both local and global. Local behavior is associated with the damage caused at the contact area of the slab and the impactor, whereas global behavior refers to the overall deformation of the slab when stress waves move away from the impact zone and travel towards the supports.

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Impact Isolation Through the Use of Compliant Interconnects for Microelectronic Packages

Journal of Electronic Packaging ◽

10.1115/1.4031680 ◽

2015 ◽

Vol 137 (4) ◽

Cited By ~ 4

Author(s):

Wei Chen ◽

Anirudh Bhat ◽

Suresh K. Sitaraman

Keyword(s):

Impact Loading ◽

Coefficient Of Thermal Expansion ◽

Low Cost ◽

Three Dimensional ◽

Simulation Data ◽

Thermally Induced ◽

Finite Element Software ◽

Drop Tests ◽

Compliant Interconnect ◽

Reliable Design

First-level and second-level compliant interconnect structures are being pursued in universities and industries to accommodate the differential displacement induced by the coefficient of thermal expansion mismatch between the die and the substrate or between the substrate and the board. The compliant interconnects mechanically decouple the die from the substrate or the substrate from the board, and thus reduce the thermally induced stresses in the assembly. This paper presents drop-test experimental and simulation data for scaled-up prototype of compliant interconnects. The simulations were based on Input-G method and performed using ANSYS® finite element software for varying drop heights. In parallel to the simulations, scaled-up compliant polymer interconnects sandwiched between a polymer die and a polymer substrate were fabricated using three-dimensional (3D) printing, and this fabrication provides a quick low-cost alternative to cleanroom fabrication. The prototype of the assembly was subjected to drop tests from varying drop heights. The response of the assembly during drop testing was captured using strain gauges and an accelerometer mounted on the prototype. The data from the experiments were compared with the predictions from the simulations. Based on such simulations, significant insight into the behavior of compliant interconnects under impact loading was obtained, which could be used for reliable design of compliant interconnect under impact loading. Both the experimental and simulation data reveal that the compliant interconnects are able to reduce the strains that transfer from substrate to die by one-order.

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