Three-Dimensional Transient Interlaminar Thermal Stresses in Angle-Ply Composites

1989 ◽  
Vol 56 (3) ◽  
pp. 601-608 ◽  
Author(s):  
Yuan Ruo Wang ◽  
Tsu-Wei Chou
Keyword(s):  
Fiber Volume Fraction ◽  
Thermal Stresses ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Free Edge ◽  
Transient Temperature ◽  
Equilibrium Equations ◽  
Fiber Volume ◽  
Thermal Boundary Conditions ◽  
Transient Temperature Field

This paper studies the three-dimensional transient interlaminar thermal stresses in elastic, angle-ply laminated composites due to sudden changes in the thermal boundary conditions. The transient temperature field and transient interlaminar thermal stresses of the laminate are obtained by solving the heat conduction equation and by a zeroth-order perturbation analysis of the equilibrium equations, respectively. Numerical results for a four-layer angle-ply laminate have shown that the interlaminar normal stress near the free edge is significantly higher than that in the interior region and it increases rapidly with the fiber volume fraction.

Simulation for Composite Forming Infusion from both inside and outside at same Time

2013 ◽  
Vol 329 ◽  
pp. 153-156
Author(s):  
Wei Xiao Du ◽  
Zhong De Shan ◽  
Feng Liu
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Fiber Volume ◽  
New Approach ◽  
High Fiber ◽  
Composite Forming ◽  
Filling Time ◽  
Infusion Method

Impregnation quality is vital to the whole composite. To improve it a new approach-infusion from both inside and outside at same time is supposed. Some comparison simulation studies, based on PAM-RTM software, are performed in this paper about the new composite forming method and traditional infusion method including flow behavior and filling time. Filling time via the two methods are compared, and the following results are obtained-It takes less time to fill the mold with infusion from both inside and outside at same time than traditional one; higher fiber volume fraction is, more favorable the new forming method is. The new infusion method is proved to be an effective and novel forming method about parts with high-thickness or high fiber content in composite forming area. The results will contribute to researches on the whole composite forming and bring prospect to provide more usages of three dimensional composites in high rank field.

Design Method for Braiding Process and Structure Parameters of Three Dimensional Two-Step Tubular Braided Preform

2010 ◽  
Vol 150-151 ◽  
pp. 1613-1616
Author(s):  
Yan Gao ◽  
Jia Lu Li
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Design Method ◽  
General Structure ◽  
Three Dimensional ◽  
Structure Parameters ◽  
Fiber Volume ◽  
General Methodology ◽  
Properties Of Composites

The properties of composites reinforced by three dimensional braided preform are determined by braiding structure significantly. The main objective of this paper is to develop a general methodology for the determination of the design and analysis of three dimensional two-step braided tubular preform. The arrangement pattern of axial yarns with various finenesses is derived for the uniform braiding structure of preform, which offers a possibility for achieving preferable interior structures of braided tubular preforms. Then, the general structure parameters, including the interrelation between surface braiding angles and interior braiding angles and the fiber volume fraction, are investigated in some detail. The results derived from this paper can provide a useful method for the design of 3D two-step tubular braided preform.

Effect of Fiber Anisotropy on Thermal Stresses in Fibrous Composites

1986 ◽  
Vol 53 (4) ◽  
pp. 751-756 ◽  
Author(s):  
W. B. Avery ◽  
C. T. Herakovich
Keyword(s):  
Fiber Volume Fraction ◽  
Maximum Stress ◽  
Thermal Stresses ◽  
Volume Fraction ◽  
Transversely Isotropic ◽  
Radial Coordinate ◽  
Stress Distributions ◽  
Matrix Interface ◽  
Fiber Volume ◽  
Fiber Matrix Interface

An elasticity solution is utilized to analyze an orthotropic fiber in an isotropic matrix under uniform thermal load. The analysis reveals that stress distributions in the fiber are singular in the radial coordinate when the radial fiber stiffness (Crr) is greater than the hoop stiffness (Cθθ). Conversely, if Crr < Cθθ the maximum stress in the composite is finite and occurs at the fiber-matrix interface. In both cases the stress distributions are radically different than those predicted assuming the fiber to be transversely isotropic (Crr=Cθθ). It is also shown that fiber volume fraction greatly influences the stress distribution for transversely isotropic fibers, but has little effect on the distribution if the fibers are transversely orthotropic.

The Tensile Properties of Three Dimensional Air Textured Aramid Reinforced Composites

2003 ◽  
Author(s):  
Thomas Brice Langston ◽  
Yiping Qiu
Keyword(s):  
Tensile Test ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Woven Composites ◽  
Reinforced Composites ◽  
Fiber Volume ◽  
Plane Shear ◽  
3D Orthogonal Woven ◽  
Lower Tensile Strength

Air-textured aramid yarns (ATAY) and regular aramid yarns (RAY) were used in this study to fabricate 3D orthogonal woven composites. The composites were tested in warp, weft, and 45° directions to determine the engineering constants of the composites. The ATAY composite had a much lower fiber volume fraction than the RAY composite due to the bulkiness of the textured yarns. With the same fiber volume fraction, the ATAY composite had a slightly lower tensile strength and modulus, but a 120% higher in-plane shear modulus, than the RAY composite. Unlike the RAY composite that demonstrated a brittle failure, the ATAY composite failed in a ductile manner with multiple diverting cracks propagating during failure. The ATAY composite had a much higher yield point in the 45° direction tensile test and a much higher softening point in the warp direction tensile test than the RAY composite. The loop entanglements of ATAY are responsible for all the improvements observed in this study.

Meso-structure and processing of three-dimensional braided material based on space group P4 symmetry

2016 ◽  
Vol 87 (14) ◽  
pp. 1765-1771 ◽  
Author(s):  
Wensuo Ma ◽  
Zhenyu Ma ◽  
Jianxun Zhu
Keyword(s):  
Structural Unit ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Point Group ◽  
Three Dimensional ◽  
Mathematic Model ◽  
Fiber Volume ◽  
Space Group ◽  
Group 4 ◽  
Novel Material

A novel three-dimensional (3D) braided material was obtained using group theory. The 3D braided structural unit was found by means of group elements in the point group 4. Based on the symmetry of space group P4, a novel 3D braided material geometry was deduced by transforming the unit. Analyzing the conceivable motion of the yarns, it was found that the geometric structure corresponding to a novel 3D braided material was feasible. The mathematic model for describing the geometry of this novel material was established. The fiber volume fraction of the material was predicted and its value is similar to the traditional four-step 3D braided material. A first prototype of the fabric is produced using manual production.

Meso-structure and modeling of a new three-dimensional braided tubular material

2017 ◽  
Vol 37 (5) ◽  
pp. 310-320 ◽  
Author(s):  
Wensuo Ma ◽  
Zhenyu Ma ◽  
Bingjie Ren ◽  
Weifeng Fan
Keyword(s):  
Mathematical Model ◽  
Structural Properties ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Geometrical Parameters ◽  
Fiber Volume ◽  
Space Group ◽  
Volume Unit ◽  
Symmetry Operations

A new three-dimensional braided tubular preform was introduced in this study. The new preform structure can be derived from the representative volume unit which was deduced by the symmetry operations of space group P4. The braiding process of the tubular preform has been discussed. A mathematical model was established to analyze the structural properties of the three-dimensional braided tubular preform. The interrelation of geometrical parameters is analyzed. The fiber volume fraction of the preform was predicted. The new tubular preform was obtained in laboratory to verify the feasibility of the braiding process.

Analysis for Temperature Field and Stress of Concrete Volute Structure

2011 ◽  
Vol 90-93 ◽  
pp. 2418-2422
Author(s):  
Xiao Bing Sun ◽  
Xue Ping Peng
Keyword(s):  
Temperature Field ◽  
Optimization Design ◽  
Thermal Stresses ◽  
Heat Waves ◽  
Water Pressure ◽  
Three Dimensional ◽  
Transient Temperature ◽  
Transient Temperature Field ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Study on temperature field and thermal stresses of a large volume concrete volute structure is important to prevent the concrete structure cracking caused by excessively tensile strains that result from the cold or heat waves and the internal water pressure. By use of the three dimensional finite element method, the displacements and stresses of a concrete volute under the external loads are calculated. The transient temperature field and the thermal stress distribution of the concrete volute caused by the cold or heat waves are obtained, and the thermo-structural coupling stress field analyses for some cases are completed detailly. The calculating results are the basis for the optimization design of the concrete volute structure.

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