scholarly journals Comparison of a load bearing capacity for composite sandwich plywood plates

2015 ◽  
Vol 1 ◽  
pp. 39 ◽  
Author(s):  
Ģirts Frolovs ◽  
Kārlis Rocēns ◽  
Jānis Šliseris
Keyword(s):  
Manufacturing Process ◽  
Weight Ratio ◽  
Longitudinal Direction ◽  
Mass Ratio ◽  
Material Consumption ◽  
Load Bearing Capacity ◽  
Core Element ◽  
Numerical Investigations ◽  
Specific Strength ◽  
Composite Sandwich

<p class="R-AbstractKeywords"><span lang="EN-US">This article shows numerical investigations of composite sandwich plywood plates with birch plywood faces and a core of straight and curved plywood honeycomb-type ribs in comparison to standard plywood plates and other core type plates. </span></p><p class="R-AbstractKeywords"><span lang="EN-US">This shape of core ribs provides several improvements for these plates in manufacturing process as well as mechanical properties. </span></p><p class="R-AbstractKeywords"><span lang="EN-US">The influence of core element shapes on stiffness in longitudinal direction of a plate is insignificant although it is possible to vary with stiffness in transverse direction of these plates by changing form of plate’s ribs. The results are describable as specific strength or stiffness (stiffness to mass or strength to mass ratio etc.) in both directions. </span></p><p class="R-AbstractKeywords"><span lang="EN-US">The various results depending on chosen variables (according to strength-stiffness criteria) plywood composite macrostructure is obtained for one span plate with uniformly distributed loading. The results show that it is possible to reduce material consumption causing reduction in stiffness but in general increasing stiffness to weight ratio for about 30% or even more if it is possible to increase height of a plate more than maximum standard plywood plate.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">All thicknesses of elements are chosen according to plywood supplier assortment.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">A various thicknesses of plywood sheets (0/90/0+90/0·n) are taken for straight ribs as well as various plates coverings for waved part of ribs the 3 layer plywood was taken (90/0/90) or (0/90/0) due to simplification of manufacturing process. </span></p><p class="R-AbstractKeywords"><span lang="EN-US">For all parts of plate were Birch plywood plates used, as well as reference plywood were Standard Birch plywood plates chosen.</span></p>

scholarly journals The energy absorption behavior of novel composite sandwich structures reinforced with trapezoidal latticed webs

2021 ◽  
Vol 60 (1) ◽  
pp. 503-518
Author(s):  
Juan Han ◽  
Lu Zhu ◽  
Hai Fang ◽  
Jian Wang ◽  
Peng Wu
Keyword(s):  
Bearing Capacity ◽  
Energy Absorption ◽  
Sandwich Structure ◽  
Ultimate Load ◽  
Sandwich Structures ◽  
Elastic Displacement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Composite Sandwich ◽  
Composite Sandwich Structures

Abstract This article proposed an innovative composite sandwich structure reinforced with trapezoidal latticed webs with angles of 45°, 60° and 75°. Four specimens were conducted according to quasi-static compression methods to investigate the compressive behavior of the novel composite structures. The experimental results indicated that the specimen with 45° trapezoidal latticed webs showed the most excellent energy absorption ability, which was about 2.5 times of the structures with vertical latticed webs. Compared to the traditional composite sandwich structure, the elastic displacement and ultimate load-bearing capacity of the specimen with 45° trapezoidal latticed webs were increased by 624.1 and 439.8%, respectively. Numerical analysis of the composite sandwich structures was carried out by using a nonlinear explicit finite element (FE) software ANSYS/LS-DYNA. The influence of the thickness of face sheets, lattice webs and foam density on the elastic ultimate load-bearing capacity, the elastic displacement and initial stiffness was analyzed. This innovative composite bumper device for bridge pier protection against ship collision was simulated to verify its performance. The results showed that the peak impact force of the composite anti-collision device with 45° trapezoidal latticed webs would be reduced by 17.3%, and the time duration will be prolonged by about 31.1%.

Influence of the Flux Ratio N2/Ar on the Formation of Mo-N Modification Layers on Ti6Al4V by Plasma Reactive Sputtering

2009 ◽  
Vol 610-613 ◽  
pp. 1128-1131
Author(s):  
Xiu Yan Li ◽  
Ying Zhang ◽  
Bin Tang ◽  
Zhong Xu
Keyword(s):  
Substrate Surface ◽  
Surface Hardness ◽  
Flux Ratio ◽  
Reactive Sputtering ◽  
Load Bearing Capacity ◽  
Specific Strength ◽  
The Poor ◽  
High Specific Strength ◽  
Composition Structure ◽  
Oriented Parallel

Ti6Al4V alloy is promising biology material with outstanding properties of low density, high specific strength, and exceptional corrosion resistance. However, one of its disadvantages is the poor tribological property. In this paper Mo-N hard surface modification layers were formed on Ti6Al4V at 900°C substrate temperature by plasma reactive sputtering. The flux ratio N2/Ar is an important parameter and its influence on the composition, structure and hardness of the Mo-N layers is studied. The Mo-N layers are duplex layers, composed of diffusing layer and surface coating. The component of Mo and N elements in the diffusing layer changes gradually which can enhance the load-bearing capacity to the coating and ensure the durability of the coating. With the increase of the flux ratio N2/Ar, the content of N element in the Mo-N layers increases. The Mo-N layers were polycrystalline γ- Mo2N with (200) plane oriented parallel to the substrate surface. The surface hardness of the formed layers is in the range HK1330-1430. The hardness of the Mo-N layers increases with the increase of the flux ratio N2/Ar and the reason is that the content of N element in the Mo-N layers increases.

Low Velocity Impact Response of Composite/Sandwich Structures

2016 ◽  
Vol 725 ◽  
pp. 127-131 ◽  
Author(s):  
Kumar V. Akshaj ◽  
P. Surya ◽  
M.K. Pandit
Keyword(s):  
Sandwich Structures ◽  
Weight Ratio ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Core Material ◽  
Design Parameters ◽  
Low Velocity ◽  
Velocity Impact ◽  
Composite Sandwich ◽  
Set Up

Dent resistance of structures is one of the important design parameters to consider in automotive, aerospace, packaging and transportation of fragile goods, civil engineering and marine industries. It is important to study the dynamic impact response of various combinations of skin and core materials which can provide desired fracture toughness and highest strength to weight ratio for such applications. This paper discusses the low velocity impact response of sandwich structures having unique combination of mild steel as skin material bonded to thermoplastics/PU foam as core material. HDPE, LDPE and polypropylene were the choice of thermoplastics and an optimum combination of materials for the sandwich structure was evaluated using drop-weight experimental set up. It is observed that LDPE is the best choice of core material for the sandwich structures considered.

scholarly journals Effect of processing parameters on the formability of recycle friendly AA5754 alloy

2020 ◽  
Vol 326 ◽  
pp. 03005
Author(s):  
Sazol Das ◽  
Matthew Heyen ◽  
John Ho ◽  
ChangOok Son
Keyword(s):  
Weight Ratio ◽  
Rolling Texture ◽  
Processing Parameters ◽  
Automotive Manufacturing ◽  
Specific Strength ◽  
Automotive Sheet ◽  
Annealing Heat Treatment ◽  
Sustainable Materials ◽  
Recycled Content ◽  
Complex Parts

AA5xxx series Al-Mg alloys possess good combination of high specific strength-to-weight ratio, formability and corrosion resistance, which makes them attractive to the automakers for their light weighting needs. Increasingly the automakers are demanding sustainable materials. Developing aluminum alloys with increased recycled content is becoming imperative. However, increasing the recycled content can negatively impact the overall formability and joinability of the alloy. Formability is important in the shaping of complex parts and it is a key requirement in automotive manufacturing. Similarly, the other key requirement for automotive sheet is joinability. Self-piercing riveting (SPR) technology is increasingly being used for joining. In this study, the process optimization of high recycle content AA5754 alloy’s for formability and rivetability will be discussed. Controlling the annealing heat treatment to produce optimum combination of grain size along with balanced recrystallized and rolling texture to improve the SPR joint configuration will be presented.

Mechanical and Morphological Properties of Sisal/Glass Fiber-Polypropylene Composites

2008 ◽  
Vol 47-50 ◽  
pp. 486-489 ◽  
Author(s):  
Kasama Jarukumjorn ◽  
Nitinat Suppakarn ◽  
Jongrak Kluengsamrong
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Weight Ratio ◽  
Morphological Properties ◽  
Fiber Reinforced ◽  
Polypropylene Composites ◽  
Specific Strength ◽  
Fiber Reinforced Polymer Composites

Natural fiber reinforced polymer composites became more attractive due to their light weight, high specific strength, biodegradability. However, some limitations e.g. low modulus, poor moisture resistance were reported. The mechanical properties of natural fiber reinforced composites can be improved by hybridization with synthetic fibers such as glass fiber. In this research, mechanical properties of short sisal-PP composites and short sisal/glass fiber hybrid composites were studied. Polypropylene grafted with maleic anhydride (PP-g-MA) was used as a compatibilizer to enhance the compatibility between the fibers and polypropylene. Effect of weight ratio of sisal and glass fiber at 30 % by weight on the mechanical properties of the composites was investigated. Morphology of fracture surface of each composite was also observed.

scholarly journals Nutritional Considerations for Bouldering

2017 ◽  
Vol 27 (4) ◽  
pp. 314-324 ◽  
Author(s):  
Edward J. Smith ◽  
Ryan Storey ◽  
Mayur K. Ranchordas
Keyword(s):  
Protein Intake ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Weight Ratio ◽  
Energy Systems ◽  
International Federation ◽  
Carbohydrate Restriction ◽  
Specific Strength ◽  
Sport Climbing ◽  
Anaerobic Energy

Bouldering competitions are held up to International level and governed by the International Federation of Sport Climbing. Bouldering has been selected to feature at the 2020 Olympic Games in Tokyo, however, physiological qualities and nutritional requirements to optimize performance remain inadequately defined due to large gaps in the literature. The primary goals of training include optimizing the capacity of the anaerobic energy systems and developing sport-specific strength, with emphasis on the isometric function of the forearm flexors responsible for grip. Bouldering athletes typically possess a lean physique, similar to the characteristics of sport climbers with reported body fat values of 6–12%. Athletes strive for a low body weight to improve power to weight ratio and limit the load on the extremities. Specialized nutritional support is uncommon and poor nutritional practices such as chronic carbohydrate restriction are prevalent, compromising the health of the athletes. The high intensity nature of bouldering demands a focus on adequate carbohydrate availability. Protein intake and timing should be structured to maximize muscle protein synthesis and recovery, with the literature suggesting 0.25–0.3 g/kg in 3–4 hr intervals. Supplementing with creatine and b-alanine may provide some benefit by augmenting the capacity of the anaerobic systems. Boulderers are encouraged to seek advice from nutrition experts to enhance performance, particularly important when weight loss is the desired outcome. Further research is warranted across all nutritional aspects of bouldering which is summarized in this review.

Modeling the interrelationship between the parameters for improving weld strength in plastic hot plate welding: A DEMATEL approach

2019 ◽  
Vol 52 (2) ◽  
pp. 117-141
Author(s):  
K Mathiyazhagan ◽  
Krishna Kumar Singh ◽  
V Sivabharathi
Keyword(s):  
Product Design ◽  
Manufacturing Process ◽  
Weight Ratio ◽  
Welding Process ◽  
High Strength ◽  
Weld Strength ◽  
Melting Time ◽  
Hot Plate ◽  
Plate Temperature ◽  
Hot Plate Welding

Application of plastics is increasing day by day since plastics offer many distinct advantages as compared to metals. Plastics has mainly good thermal and electrical insulation properties, corrosion resistance, chemical inertness, and high strength to weight ratio. Additionally, these are cheaper in cost as compared to conventional materials. Plastics are additionally easy to process. Nowadays, product requirements are getting critical and thus product design is getting more complex in shape. To manufacture intricate complex shape creates complexity in manufacturing process which is sometimes very difficult or almost not feasible to produce with single manufacturing process. To manufacture such critical products, welding is a complimentary process. Type of weld joint and welding process can be selected based on the product design and load application on the product. Hot plate welding is very simple welding process as compared to other plastic welding process and most commonly used. Good quality weld is the prime objective of welding process. Weld strength is dependent on several parameters which may be process parameters as well as product parameters. The objective of this study is to identify the key parameters in hot plate welding process of the plastics using Decision Making Trial and Evaluation Laboratory which is one of the prioritization techniques. Results of the study focus on understanding the key parameters affecting the weld strength. Study shows that hot plate temperature, welding time, and melting time are the key parameters affecting the weld strength.

scholarly journals Fatigue Cycles and Performance Evaluation of Accelerating Aging Heat Treated Aluminum Semi Solid Materials Designed for Automotive Dynamic Components

2020 ◽  
Vol 10 (9) ◽  
pp. 3008
Author(s):  
Mohamed Attia ◽  
Khaled Ahmed Ragab ◽  
Mohamed Bouazara ◽  
X.-Grant Chen
Keyword(s):  
Fatigue Life ◽  
Thermal Aging ◽  
Weight Ratio ◽  
Dynamic Component ◽  
Specific Strength ◽  
Suspension Control ◽  
Dynamic Components ◽  
Semi Solid ◽  
Automotive Suspension ◽  
Von Mises

The A357-type (Al-Si-Mg) aluminum semi solid casting materials are known for their excellent strength and good ductility, which make them materials of choice, preferable in the manufacturing of automotive dynamic mechanical components. Semi-solid casting is considered as an effective technique for the manufacturing of automotive mechanical dynamic components of superior quality performance and efficiency. The lower control arm in an automotive suspension system is the significant mechanical dynamic component responsible for linking the wheels of the vehicle to the chassis. A new trend is to manufacture this part from A357 aluminum alloy due to its lightweight, high specific strength, and better corrosion resistance than steel. This study proposes different designs of a suspension control arm developed, concerning its strength to weight ratio. Furthermore, this study aims to investigate the effect of accelerating thermal aging treatments on the fatigue life of bending fatigue specimens manufactured from alloy A357 using the Rheocasting semi-solid technology. The results revealed that the multiple aging cycles, of WC3, indicated superior fatigue life compared to standard thermal aging cycles. On the other hand, the proposed designs of automotive suspension control components showed higher strength-to-weight ratios, better stress distribution, and lower Von-Mises stresses compared to conventional designs.

scholarly journals Influence of incubation time on the vibration and mechanic properties of mycowood

Holzforschung ◽  
2016 ◽  
Vol 70 (6) ◽  
pp. 557-565 ◽  
Author(s):  
Marjan Sedighi Gilani ◽  
Jürg Neuenschwander ◽  
Markus Heeb ◽  
Roman Furrer ◽  
Sergio J. Sanabria ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sound Velocity ◽  
Treatment Time ◽  
Characteristic Impedance ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Longitudinal Direction ◽  
White Rot ◽  
White Rot Fungus ◽  
Fungal Treatment

Abstract The goal of the current study was to investigate the physical and mechanical properties of mycowood as a high quality tone-wood, obtained from Norway spruce by treatment of the white rot fungus Physisporinus vitreus as a function of the treatment time. In focus was the stiffness to weight ratio, which is often considered a main criterion for tone-wood selection. The vibro-mechanical properties were tested by non-destructive methods. The change of color and density were also measured after 4–12 months of fungal incubation. Density decreased up to 5% after 12 months of fungal treatment. Sound velocity was measured in small size specimens by means of the free-free vibration approach, while in large specimens the air-coupled ultrasound method was applied. The two techniques gave similar results and indicated that the sound velocity decreased in mycowood. Internal damping was increased in mycowood to a higher extent than the reduction in the specific modulus of elasticity (E/ρ) and thus the sound velocity in the material. The sound velocity was decreasing with increasing incubation times and scattering of data with this regard was larger in the transversal than in the longitudinal direction. The sound radiation coefficient and the characteristic impedance were enhanced in mycowood and its color was more brownish and richer in tone.

scholarly journals Mechanical Characterization of Rapid Solidified Alsicumg Alloys by New CRSS Casting Method Under T6 Condition

2019 ◽  
Vol 8 (12) ◽  
pp. 2897-2902
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Process ◽  
High Performance ◽  
Weight Ratio ◽  
Solidification Process ◽  
Casting Process ◽  
Casting Method ◽  
Silicon Alloys ◽  
Hardness Tester

Aluminum-silicon alloys acquiring extensive industrial attention due to their superior resistance to rate of wear and elevated strength to weight ratio properties. Though the properties of the materials substantially depend on the manufacturing process they involve. Thus many industries focusing on new manufacturing methods to produce high-performance alloys. In this present study, AlSi (16-18) alloys were prepared by new CRSS (combined rheo stir squeeze) casting method with rapid-solidification process under T-6 condition. CRSS-T6 as casting process enhances the microstructural and mechanical properties significantly by 40-70%. Whereas, the maximum value of hardness (179.37) was found with AlSi17Cu3.5Mg0.8 with CRSS-T6. The improvements in hardness and elastic properties were mainly ascribed to size, distribution, and morphology of Si-particles because of its manufacturing process. SEM, advanced metallurgical microstructure and EDS analysis techniques are used for the surface morphologies observation. Moreover, Brinell hardness tester and Tensometer are used for the characterization of mechanical properties

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