Design of Steel-Concrete Composite Structures Using High-Strength Materials

2021 ◽  
Keyword(s):  
Composite Structures ◽  
High Strength

PROGRESSIVE DAMAGE FAILURE ANALYSIS OF POST-BUCKLED COMPOSITE SINGLE-STRINGER PANEL WITH TEFLON INSERTS

2021 ◽  
Author(s):  
VIJAY K. GOYAL ◽  
AUSTIN PENNINGTON ◽  
JASON ACTION
Keyword(s):  
Experimental Data ◽  
Composite Structures ◽  
Laminated Composites ◽  
Compressive Loading ◽  
Weight Ratio ◽  
High Strength ◽  
Material Model ◽  
Stiffened Panels ◽  
Damage Initiation ◽  
Critical Aspects

The high strength-to-weight and stiffness-to-weight ratio materials, such as laminated composites, are advantageous for modern aircraft. Laminated composites with initial flaws are susceptible to delamination under buckling loads. PDA tools help enhance the industry’s understanding of the mechanisms for damage initiation and growth in composite structures while assisting in the design, analysis, and sustainment methods of these composite structures. The global-local modeling approach for the single-stringer post-buckled panel was evaluated through this effort, using Teflon inserts to simulate the defect of damage during manufacturing. This understanding is essential for designing the post-buckled structure, reducing weight while predicting damage initiation location, and addressing a potential design review for future aircraft repairs. In this work, the initial damage was captured with Teflon inserts as the starting configuration; and any reference to the damage initiation refers to any damage beyond the “initial unbonded region.” The effort aims to develop, evaluate, and enhance methods to predict damage initiation and progression and the failure of post-buckled hat-stiffened panels using multiple Abaqus FEA Virtual Crack Closure Technique (VCCT) definitions. Validation of the PDA using the VCCT material model was performed on a large single-stringer panel subjected to compressive loading. The compressive loading of the panel caused the skin to buckle before any damage began to occur locally. In addition, comparisons are made for critical aspects of the damage morphology, such as a growth pattern that included delamination from the skin-stiffener interface to the skin and ply interfaces. When compared against the experimental data produced through the NASA Advanced Composites Project (ACP), the present model captured damage migration from one surface to another, and model validations were ~5% of the experimental data.

Study of Strength and Deformation Properties of the Composite Reinforcing Bar from the Continuous Basalt Fiber

2020 ◽  
Vol 1013 ◽  
pp. 132-138
Author(s):  
L.Yu. Stupishin ◽  
S.G. Emelyeanov ◽  
E.V. Savelyeva ◽  
M.L. Moshkevich
Keyword(s):  
Composite Structures ◽  
Test Procedure ◽  
Basalt Fiber ◽  
High Strength ◽  
Test Method ◽  
Strength Characteristics ◽  
Reinforcing Bar ◽  
Low Weight ◽  
Deformation Properties ◽  
Weight One

Composite structures require the use of modern reinforcing materials combining high strength characteristics and resistance to aggressive influences with low weight. One of the promising materials for the production of reinforcing products is basalt roving. The high strength of the thread in combination with fragility imposes certain limitations on its placement in the material, and requires new approaches to the design of the reinforcing bar itself. The article investigates the strength characteristics of a composite reinforcing bar made of a basalt complex thread proposed by the authors. The features of the test procedure and the mechanical characteristics of the reinforcing material are described. The effectiveness of the applied test method developed in the process of testing reinforcing rods is shown. An increase in the tensile strength of a composite reinforcing bar based on basalt fiber is established in comparison with products from fiber and roving.

scholarly journals Behavior of an Advanced Bolted Shear Connector in Prefabricated Steel-Concrete Composite Beams

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2958 ◽  
Author(s):  
Jun Chen ◽  
Wei Wang ◽  
Fa-Xing Ding ◽  
Ping Xiang ◽  
Yu-Jie Yu ◽  
...  
Keyword(s):  
Composite Structures ◽  
Concrete Slab ◽  
Concrete Strength ◽  
High Strength ◽  
Fe Model ◽  
Building Structures ◽  
Shear Connector ◽  
Test Results ◽  
Shear Connectors ◽  
Bolt Pretension

The high-strength bolt shear connector in prefabricated concrete slab has advantages in applications as it reduces time during the construction of steel-concrete composite building structures and bridges. In this research, an innovative and advanced bolt shear connector in steel-concrete composite structures is proposed. To investigate the fundamental mechanical behavior and the damage form, 22 static push-off tests were conducted with consideration of different bolt dimensions, the reserved hole constraint condition, and the dimension of slab holes. A finite element (FE) model was established and verified by using test results, and then the model was utilized to investigate the influence of concrete strength, bolt dimension, yield strength, bolt pretension, as well as length-to-diameter ratio of high strength bolts on the performances of shear connectors. On the basis of FE simulation and test results, new design formulas for the calculation of shear resistance behavior were proposed, and comparisons were made with current standards, including AISC, EN 1994-1-1, GB 50017-2017, and relevant references, to check the calculation efficiency. It is confirmed that the proposed equation is in better agreement with the experimental results.

A Component-Wise Approach to Analyse a Composite Launcher Structure Subjected to Loading Factor

2016 ◽  
Author(s):  
Tommaso Cavallo ◽  
Alfonso Pagani ◽  
Enrico Zappino ◽  
Erasmo Carrera
Keyword(s):  
Composite Structures ◽  
Computational Cost ◽  
Free Vibration Analysis ◽  
High Strength ◽  
3D Models ◽  
Advanced Materials ◽  
Space Structures ◽  
One Dimensional ◽  
Computational Costs ◽  
The One

The space structures are realized by combining skin and reinforced components, such as longitudinal reinforcements called stringers and transversal reinforcements called ribs. These reinforced structures allow two main design requirements to be satisfied, the former is the light weight and the latter is a high strength. Solid models (3D) are widely used in the Finite Element Method (FEM) to analyse space structures because they have a high accuracy, in contrast they also have a high number of degrees of freedoms (DOFs) and huge computational costs. For these reasons the one-dimensional models (1D) are gaining success as alternative to 3D models. Classical models, such as Euler-Bernoulli or Timoshenko beam theories, allow the computational cost to be reduced but they are limited by their assumptions. Different refined models have been proposed to overcome these limitations and to extend the use of 1D models to the analysis of complex geometries or advanced materials. In this work very complex space structures are analyzed using 1D model based on the Carrera Unified Formulation (CUF). The free-vibration analysis of isotropic and composite structures are shown. The effects of the loading factor on the natural frequencies of an outline of launcher similar to the Arian V have been investigated. The results highlight the capability of the present refined one-dimensional model to reduce the computational costs without reducing the accuracy of the analysis.

scholarly journals A Review Of Mechanisms And Fracture Mechanics Of Moisture Ingress In Composite Systems

2021 ◽  
Author(s):  
Janani S. Gopu
Keyword(s):  
Fracture Mechanics ◽  
Composite Structures ◽  
Composite System ◽  
Aerospace Industry ◽  
Weight Ratio ◽  
High Strength ◽  
Honeycomb Structure ◽  
Sandwich Composite ◽  
Composite Systems ◽  
Water Accumulation

Composite materials help realize high strength to weight ratio requirements of the Aerospace Industry. Composite structures and sandwich composite structures are susceptible to moisture ingress. Moisture ingress causes degradation of thermo-mechanical properties of the composite panels. Water accumulation in sandwich composite structures causes rapid degradation of face to core bondline, damage of cells frozen water and even blow off skins owing to sudden pressure build up in the cells of the honeycomb structure. Mechanisms of moisture ingress can be broadly classified into direct and indirect mechanisms. Direct ingress occurs through pre-existing pathways formed by defects in the composite system. Indirect mechanisms are diffusion, Capillary actions, Wicking actions, and Osmosis. The first form of damage in FRP materials is microcracking. The rate of microcracking increases with moisture ingress. Microcracking fracture toughness is a material property for the susceptibility of a composite system to the formation of microcracks. This work implores the mechanisms and the fracture mechanics dominating the formation of microcracks.

scholarly journals Digital Shearography for NDT: Phase Measurement Technique and Recent Developments

2018 ◽  
Vol 8 (12) ◽  
pp. 2662 ◽  
Author(s):  
Qihan Zhao ◽  
Xizuo Dan ◽  
Fangyuan Sun ◽  
Yonghong Wang ◽  
Sijin Wu ◽  
...  
Keyword(s):  
Composite Materials ◽  
Measurement Technique ◽  
Composite Structures ◽  
Phase Measurement ◽  
High Sensitivity ◽  
High Strength ◽  
Development Trend ◽  
New Techniques ◽  
Low Weight ◽  
Recent Developments

Composite materials have seen widespread use in the aerospace industry and are becoming increasingly popular in the automotive industry due to their high strength and low weight characteristics. The increasing usage of composite materials has resulted in the need for more effective techniques for nondestructive testing (NDT) of composite structures. Of these techniques, digital shearography is one the most sensitive and accurate methods for NDT. Digital shearography can directly measure strain with high sensitivity when combined with different optical setups, phase-shift techniques, and algorithms. Its simple setup and less sensitivity to environmental disturbances make it particularly well suited for practical NDT applications. This paper provides a review of the phase measurement technique and recent developments in digital shearographic NDT. The introduction of new techniques has expanded the range of digital shearography applications and made it possible to measure larger fields and detect more directional or deeper defects. At the same time, shearography for different materials is also under research, including specular surface materials, metallic materials, etc. Through the discussion of recent developments, the future development trend of digital shearography is analyzed, and the potentials and limitations are demonstrated.

Preliminary Design of Tubular Composite Structures Using Netting Theory and Composite Degradation Factors

1995 ◽  
Vol 117 (4) ◽  
pp. 390-394 ◽  
Author(s):  
B. W. Tew
Keyword(s):  
Corrosion Resistance ◽  
Composite Materials ◽  
Cyclic Loading ◽  
Composite Structures ◽  
High Strength ◽  
Preliminary Design ◽  
Light Weight ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Design Calculations

Tubular products and process vessels built using fiber-reinforced composite materials provide significant advantages in applications that require corrosion resistance, high strength, and light weight. A design approach based on netting theory is presented which enables engineers to develop preliminary structural designs for these structures using composite materials. The integration of creep, cyclic loading, and environmental degradation factors into initial design calculations is also discussed and illustrated.

Tensile Properties of Angle Cured Laminated Composites Structures under Gravity Effects

2013 ◽  
Vol 465-466 ◽  
pp. 101-105
Author(s):  
Mohd Yuhazri bin Yaakob ◽  
T.T.T. Jennise ◽  
H. Sihombing ◽  
Md Radzai bin Said ◽  
U. Nirmal ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Composite Structures ◽  
Weight Ratio ◽  
Laminated Composite ◽  
High Strength ◽  
Maximum Force ◽  
Composites Materials ◽  
Laminated Composite Structures ◽  
Gravity Effects ◽  
Optimum Productivity

As the usage of composites materials are significant in the industries of automobiles, shipping and constructions due to their non-corrosive and high strength to weight ratio. Anyway, the production of composites needed to be increased to meet the demand. At this stage, problem faced by Small and Medium Industries / Entrepreneurs (SMI/E) is the confined and limited space available that restricts the optimum productivity. They commonly cure the composites horizontally that requires ample space and unable to afford for high-end equipment such as mechanical oven and autoclave in the production as a result of high capital cost.This research is carried out to study the feasibility of the gravity effects on curing position of the laminated composite structures to enhance the curing space needed. The aim of the research was to investigate the tensile properties of the thermosetting laminated composite by curing the laminate at different angle using vacuum bagging technique. From the testing, SN 5 which denominated to be 60 ̊ found to have the best tensile properties in term of maximum force exerted and Youngs modulus.

scholarly journals Local Damage Indices of Frames Consisting of Composite Beams and RC Columns

2016 ◽  
Vol 10 (1) ◽  
pp. 280-292
Author(s):  
Wei Li ◽  
Linzhu Sun ◽  
Kejia Yang ◽  
Lei Wang ◽  
Dongyan Wu ◽  
...  
Keyword(s):  
Composite Structures ◽  
Damage Model ◽  
Damage Index ◽  
High Strength ◽  
Steel Beams ◽  
Local Damage ◽  
Composite Frame ◽  
Damage Indices ◽  
Study Results ◽  
Scope Of Application

The study is to propose the local damage indices of composite frame structures consisting of high-strength concrete columns confined by continuous compound spiral ties and steel beams (CCSTRCS), the local damage indices would lay a foundation for the study of the overall damage indices for composite CCSTRCS frame. The Mehanny damage model has been modified to predict the local damage behavior of composite CCSTRCS frames, it enlarges the scope of application for the composite structures compared with the previous work. The proposed model is validated by comparing with the present references. The study results suggest the different components corresponding to the extent of the damage and its damage index.

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