scholarly journals Numerical and experimental investigation of out-of-plane fiber waviness on the mechanical properties of composite materials

2020 ◽  
Author(s):  
M. Thor ◽  
U. Mandel ◽  
M. Nagler ◽  
F. Maier ◽  
J. Tauchner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Composite Materials ◽  
Fiber Waviness ◽  
Out Of Plane

Influences of in-plane and out-of-plane fiber waviness on mechanical properties of carbon fiber composite laminate

2018 ◽  
Vol 37 (13) ◽  
pp. 877-891 ◽  
Author(s):  
Chenjun Wu ◽  
Yizhuo Gu ◽  
Liang Luo ◽  
Peng Xu ◽  
Shaokai Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Failure Modes ◽  
Fiber Composite ◽  
Charpy Impact ◽  
Compressive Property ◽  
Mechanical Degradation ◽  
Carbon Fiber Composite ◽  
Fiber Waviness ◽  
Out Of Plane

Based on the curing process of carbon fiber/epoxy prepreg with autoclave, two kinds of unidirectional carbon fiber laminates with in-plane and out-of-plane waviness were fabricated by rolling prefabricated out-of-plane waviness and inserting prepreg strip, respectively. Fiber waviness defects in composites were characterized by waviness ratio. The specimens containing fiber waviness were successfully prepared with almost the same fiber content and low porosity. The influences of fiber waviness with different waviness ratio on tensile, compressive, and charpy impact properties of unidirectional laminates were studied, and the corresponding failure modes were observed. The mechanism of the effects of fiber waviness on mechanical properties was discussed. The experimental results show that tensile property and compressive property decrease by in-plane buckling and out-of-plane wrinkling, especially with large waviness ratio. Reduction of 33.0% of compressive strength with out-of-plane wrinkling is seen in the case of 0.037 waviness ratio, while 25.4% reduction is obtained for in-plane buckling under 0.038 waviness ratio. Charpy impact strength decreases by in-plane buckling, whereas increases by out-of-plane wrinkling. Failure morphologies of various specimens are changed by fiber waviness, which are consistent with the mechanical degradation. In addition, there are some differences on the sensitivity of mechanical properties to different types of fiber waviness. Tensile strength is more sensitive to in-plane buckling in comparison with out-of-plane wrinkling, and compressive property is more sensitive to out-of-plane wrinkling.

Anti-Tetrachiral Auxetic Structures Fabricated by Material Extrusion: Numerical and Experimental Investigation on Mechanical Properties Under Compressive Loading

2021 ◽  
Author(s):  
Soham Kantilal Teraiya ◽  
Swapnil Vyavahare ◽  
Shailendra Kumar
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Compressive Loading ◽  
Design Parameters ◽  
Material Extrusion ◽  
Response Characteristics ◽  
Out Of Plane ◽  
Auxetic Structures ◽  
Face Centered ◽  
Grey Relational

Abstract The present article describes a numerical and experimental investigation on mechanical properties of anti-tetrachiral auxetic structures under compressive loading. The structures of ABS material are fabricated by material extrusion (ME) technique of additive manufacturing (AM). The influence of design parameters, namely node radius and ligament thickness, is studied on responses including strength, modulus and specific energy absorption (SEA) of the in-plane and out-of-plane oriented structure. The experiments are planned using face-centered central composite design and the results are analyzed using analysis of variance (ANOVA). From the experimental study, it is found that both design parameters significantly influence the response characteristics of structures. In case of compression loading of in-plane oriented structures, strength and modulus increase with a decrease in node radius and increase in ligament thickness, while SEA increases with a decrease in node radius and ligament thickness. In case of out-of-plane orientation, strength and modulus increase with an increase in node radius and ligament thickness, while SEA increases with an increase in node radius and decrease in ligament thickness. Further, regression models are developed and optimization is performed using grey relational analysis (GRA) to maximize the responses.

scholarly journals Mechanisms of Origin and Classification of Out-of-Plane Fiber Waviness in Composite Materials—A Review

2020 ◽  
Vol 4 (3) ◽  
pp. 130
Author(s):  
Michael Thor ◽  
Markus G. R. Sause ◽  
Roland M. Hinterhölzl
Keyword(s):  
Composite Materials ◽  
Process Development ◽  
Influence Factors ◽  
Design Stage ◽  
Fiber Waviness ◽  
Load Carrying ◽  
Out Of Plane ◽  
Product And Process ◽  
The Impact

Out-of-plane fiber waviness, also referred to as wrinkling, is considered one of the most significant effects that occur in composite materials. It significantly affects mechanical properties, such as stiffness, strength and fatigue and; therefore, dramatically reduces the load-carrying capacity of the material. Fiber waviness is inherent to various manufacturing processes of fiber-reinforced composite parts. They cannot be completely avoided and thus have to be tolerated and considered as an integral part of the structure. Because of this influenceable but in many cases unavoidable nature of fiber waviness, it might be more appropriate to consider fiber waviness as effects or features rather than defects. Hence, it is important to understand the impact of different process parameters on the formation of fiber waviness in order to reduce or, in the best case, completely avoid them as early as possible in the product and process development phases. Mostly depending on the chosen geometry of the part and the specific manufacturing process used, different types of fiber waviness result. In this study, various types of waviness are investigated and a classification scheme is developed for categorization purposes. Numerous mechanisms of wrinkling were analyzed, leading to several recommendations to prevent wrinkle formation, not only during composite processing, but also at an earlier design stage, where generally several influence factors are defined.

Effect of Z-Pin on the through-the-Thickness Strength of Woven Composite Laminates

2010 ◽  
Vol 123-125 ◽  
pp. 47-50 ◽  
Author(s):  
J.H. Son ◽  
Heoung Jae Chun ◽  
K.T. Kang ◽  
H.Y. Lee ◽  
Joon Hyung Byun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Composite Laminates ◽  
Thickness Direction ◽  
Woven Composite ◽  
Suggested Model ◽  
Plane Shear ◽  
Out Of Plane ◽  
Woven Composite Laminates

Delamination failure occurs due to the out-of-plane loading because of the weakness in the thickness directional properties of composite materials. The z-pinned composite has been developed to overcome such a problem. In this study, the mechanical properties of z-pinned composite laminates were examined using the analytical model. The effects of z-pins on the strength in the thickness direction were investigated. Fibers in the laminate are gradually waved by the formation of resin rich zone caused by inserting the z-pins. A constitutive model was developed for the predictions of strengths of woven z-pinned composites. The changes in the strengths in the in-plane and out-of-plane directions of the woven z-pinned composites and the effects of controlling parameters such as the diameter of z-pin and densities of z-pin on the strengths were identified. It was found that the out-of-plane tensile strength increases 14% relative to that of composite without z-pins when the diameter of z-pin is 0.25 mm. However, the in-plane tensile strength and in-plane and out-of-plane shear strengths were reduced to 9%, 7% and 8%, respectively, over the strengths of composite without z-pins. Qualitatively good correlations are obtained between the results of the suggested model and the experiments.

Effects of particle sizes, wood to cement ratio and chemical additives on the properties of sesendok (Endospermum Diadenum) cement-bonded particleboard

2010 ◽  
Vol 7 (2) ◽  
pp. 57
Author(s):  
Jamaludin Kasim ◽  
Shaikh Abdul Karim Yamani ◽  
Ahmad Firdaus Mat Hedzir ◽  
Ahmad Syafiq Badrul Hisham ◽  
Mohd Arif Fikri Mohamad Adnan
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Cement Content ◽  
Particle Sizes ◽  
Thickness Swelling ◽  
Chemical Additives ◽  
Board Density ◽  
Cement Ratio ◽  
Aluminium Silicate ◽  
Cement Board

An experimental investigation was performed to evaluate the properties of cement-bonded particleboard made from Sesendok wood. The target board density was set at a standard 1200 kg m". The effect offarticle size, wood to cement ratio and the addition ofsodium silicate and aluminium silicate on the wood cement board properties has been evaluated. A change ofparticle size from 1.0 mm to 2.0 mm has a significant effect on the mechanical properties, however the physical properties deteriorate. Increasing the wood to cement ratio from 1:2.25 to 1:3 decreases the modulus ofrupture (MOR) by 11% and the addition ofsodium silicate improves valuesfurther by about 28% compared to the addition ofaluminum silicate. The modulus ofelasticity (MOE) in general increases with increasing cement content, but is not significantly affected by the addition ofsodium silicate or aluminium silicate, although the addition of their mixture (sodium silicate andaluminium silicate) consistentlyyields greater MOE values. Water absorption and thickness swelling is significantly affected by the inclusion ofadditives and better values are attained using higher wood to cement ratios.

Aging of polymer composite materials under loading. (See Beginning in #10-2020)

2020 ◽  
pp. 2-12
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Cyclic Loads ◽  
Reinforced Plastics ◽  
Water Exposure ◽  
Laboratory Conditions ◽  
Bending Loads ◽  
Moisture Conditions

A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.

Aging of polymer composite materials under loading

2020 ◽  
pp. 7-18
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Cyclic Loads ◽  
Reinforced Plastics ◽  
Water Exposure ◽  
Laboratory Conditions ◽  
Bending Loads ◽  
Moisture Conditions

A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.

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