scholarly journals Mechanical Properties of Glued-Laminated Timber with Different Assembly Patterns

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Shan Gao ◽  
Man Xu ◽  
Nan Guo ◽  
Ying Zhang
Keyword(s):  
Mechanical Properties ◽  
Bending Stiffness ◽  
Experimental Results ◽  
Bending Test ◽  
Material Strength ◽  
Lower Grade ◽  
Stiffness Reduction ◽  
Glued Laminated Timber ◽  
Bending Behavior ◽  
The Cost

A glued-laminated timber section with mixed-grade laminae could make an efficient use of material strength and reduce the cost. A 4-point bending test was conducted on a total of 18 specimens to investigate the mechanical properties of glued-laminated timber. Uniform-grade, asymmetrical mixed-grade, and symmetrical mixed-grade patterns were used to assemble the beam sections. The bending stiffness and reliability of the beams were assessed according to the experimental results. The influence of the assembly pattern on the bending behavior of glued-laminated timber was investigated by finite element models. The results show that the assembly pattern of the section has little influence on the failure mode of glued-laminated timber. Relative lower strength in compressive area of the section is beneficial for delaying the occurrence of the first crack on the glued-laminated timber beam. An equation for apparent bending stiffness of glued-laminated timber was proposed, whose results match well with the experimental results. The beam section assembled by the asymmetrical mixed-grade pattern retains the higher level of safety compared to those assembled by uniform-grade and symmetrical mixed-grade patterns. The grade of the second bottom lamina in tensile has little influence on the performance of glued-laminated timber, while lower grade laminae in compressive area of the section would cause a bending stiffness reduction at smaller deflection.

Study on bending and tensile properties of a T-shaped hook-connected structure made of two-and-a-half-dimensional woven composites and laminated composites

2019 ◽  
Vol 89 (19-20) ◽  
pp. 4046-4059 ◽  
Author(s):  
Hongjian Zhang ◽  
Junhua Guo ◽  
Weidong Wen ◽  
Haitao Cui ◽  
Shu He
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Bending Strength ◽  
Laminated Composites ◽  
Prediction Method ◽  
Experimental Results ◽  
Bending Test ◽  
Woven Composites ◽  
Root Edge ◽  
Connected Structure

In this paper, a kind of T-shaped hook-connected structure, which consists of a T-shaped plate made of two-and-a-half-dimensional woven composites and a groove structure made of T300/BMP316 laminated composites, was designed as the simulator specimen of the connection structure between the vane and the case in an aero-engine. As the bending strength and tensile strength are important mechanical properties, bending tests and tensile tests, respectively, of the T-shaped hook-connected structure were conducted to study the mechanical properties and failure modes under bending and tensile loads on web. Experimental results showed that the initial damages both occur at the root-edge, and then the damages extend to the root-middle during the bending test or extend perpendicular to the root-edge to the margin of the flange during the tensile test. Then, a strength prediction method based on the progressive damage theory was developed to simulate the mechanical properties and damage processes of the T-shaped hook-connected structure under bending and tensile loads, respectively. Compared with experimental results, the maximum error is less than 10%, and the damage modes are similar.

Experimental Investigation on Tensile Mechanical Properties of CFRP-PCPs Composite Rebars

2012 ◽  
Vol 204-208 ◽  
pp. 4602-4605
Author(s):  
Jiong Feng Liang ◽  
Huang Lei ◽  
Zhi Ping Deng
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Tensile Test ◽  
Concrete Strength ◽  
High Strength ◽  
Reinforcement Ratio ◽  
Experimental Results ◽  
Structural Requirements ◽  
Tension Stiffening ◽  
The Cost

The behavior of CFRP-PCPs composite rebars on tensile test was studied. Experimental results showed that using CFRP-PCP composite rebars as reinforcement utilizes high strength of FRP effectively, reducing the reinforcement ratio and consequently the cost while simultaneously satisfying structural requirements. Tension stiffening in CFRP-PCPs composite rebars is significant when higher concrete strength and higher prestressing level are applied.

scholarly journals Bending Behavior of Lightweight Wood-Based Sandwich Beams with Auxetic Cellular Core

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1723 ◽  
Author(s):  
Krzysztof Peliński ◽  
Jerzy Smardzewski
Keyword(s):  
Mechanical Properties ◽  
Experimental Studies ◽  
Numerical Calculations ◽  
Bending Test ◽  
Dissipated Energy ◽  
Sandwich Beams ◽  
Wood Composites ◽  
Three Point Bending ◽  
Good Ability ◽  
Bending Behavior

The work concerns a three-point bending test of beams made of plywood, high density fibre boards, cardboard, and wood-epoxy mass. The goal of the investigation was to determine the effect of thickness and type of wood-based facings on stiffness, strength, ability to absorb, and dissipate the energy of sandwich beams with an auxetic core. The cognitive goal of the work was to demonstrate the possibility of using recycled materials for facings and cores instead of popular wood composites. Experimental studies and numerical calculations were performed on correctly calibrated models. Experimental studies have shown that the beams with HDF facings (E = 1528 MPa, MOR = 12.61 MPa) and plywood facings (E = 1248–1395 MPa, MOR = 8.34–10.40 MPa) have the most favourable mechanical properties. Beams with plywood facings also have a good ability to absorb energy (1.380–1.746 J), but, in this respect, the beams manufactured of HDF (2.223 J) exhibited better capacity. The use of an auxetic core and facings of plywood and cardboard significantly reduces the amount of dissipated energy (0.0093 J, 0.0067 J). Therefore, this type of structures can be used for modeling beams carrying high deflections.

scholarly journals The Influence of Environmental Conditions on Automated Fabric Handling

1998 ◽  
Vol 10 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Paul M. Taylor ◽  
◽  
Didier M. Pollet ◽  
Paul J. W. Abbott ◽  
Keyword(s):  
Environmental Conditions ◽  
Material Properties ◽  
Intelligent Systems ◽  
Bending Stiffness ◽  
Experimental Results ◽  
Friction Coefficients ◽  
Pick And Place ◽  
Place Task ◽  
The Cost ◽  
Fabric Handling

The automation of garment assembly has proved to be very difficult to achieve with the cost, flexibility and reliability required by the manufacturers. The importance of two fabric properties, friction and bending stiffness, is emphasised, with a focus on a pick and place task. It is also shown that changes in humidity can cause significant changes in the unloaded friction coefficients and the bending stiffnesses of fabrics and thus affect the task operation. Both theoretical and experimental results are given. This leads to three possible approaches: close regulation of the materials and processes, handling processes tolerant to changes in the material properties, and thirdly, intelligent systems which can learn from and adapt to each situation.

scholarly journals 3-D analytical model for bending stiffness of thick-walled composite hollow shaft

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110047
Author(s):  
Mo Yang ◽  
Yuebin Zhou ◽  
Xian Zhou ◽  
Jianmin Ye ◽  
Yikun Wang ◽  
...  
Keyword(s):  
Analytical Model ◽  
Analytical Method ◽  
Mechanical Analysis ◽  
Bending Stiffness ◽  
Experimental Results ◽  
Bending Test ◽  
Stacking Sequence ◽  
Hollow Shaft

In this paper, the Layer-wise theory was improve based on the alternate characteristics of layer angle of composite hollow shaft. The ±φi laminate was considered as the minimum mechanical analysis element, which can effectively simplify the stress coupling in mechanical analytical method. On this foundation, a 3-D analytical method of bending stiffness < EI> for thick-walled composite hollow shaft was derived. The CFRP hollow shaft specimens made of same dimensions but different laminate were used for bending test. Then, the bending stiffness calculated by theory of beams, 2-D analytical method, 3-D analytical model and experiment were compared. All the results show that the 3-D analytical model predicts the bending stiffness of thick-walled composite hollow shaft more precisely than the theory of beams and analytical method, and agree well with experimental results. And the 3-D analytical model can reflect the influence of stacking sequence on the bending stiffness of the composite hollow shaft.

Effects of TiH2 on the Properties of Fe-Based Diamond Composites

2005 ◽  
Vol 291-292 ◽  
pp. 27-32 ◽  
Author(s):  
Qiu Lian Dai ◽  
Xi Peng Xu
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Metal Matrix ◽  
Experimental Results ◽  
Bending Test ◽  
The Matrix ◽  
Base Matrix ◽  
Circular Sawing ◽  
Saw Blade ◽  
Worn Surface

Effects of TiH2 on the mechanical properties and microstructures of Fe-based diamond composites as well as the performance of diamond segments in circular sawing of granites are presented in this paper. Experimental results reveal that the addition of 2%TiH2 into the Fe-based matrix leads to decreases in the mechanical properties of both matrix and diamond composites. The wear resistance of the saw-blade segments decreases by 7.3%. Microscope observations reveal that the specimen without TiH2 shows fewer pores and denser structures in the base matrix. The fracture surfaces of the bending test specimens exhibit ductile cup and cone behavior and strong bonding between the matrix and diamond. SEM micrographs indicate that there are much more pull-outs of diamond grits, much more serious wear of diamond particles and erosion of metal matrix on the worn surface of saw-blades segments with 2% TiH2 in the matrix.

Synthesis of Silica Microspheres Filler for PDMS

2013 ◽  
Vol 650 ◽  
pp. 190-193 ◽  
Author(s):  
Wen Juan Gu ◽  
Ying Li ◽  
Xiao Hui Zhang ◽  
Hou Bin Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Sol Gel ◽  
Hybrid Membrane ◽  
Experimental Results ◽  
Silica Microspheres ◽  
Gel Method ◽  
Ir Analysis ◽  
The Cost ◽  
Effective Reinforcement

A new kind of silica microspheres were first synthesized with chloropropyltrimethoxysilane (WD30) and tetraethoxysilane (TEOS) by sol-gel method. And hybrid membrane was prepared by incorporating the as prepared filler into polydimethylsiloxane (PDMS). The IR, swelling density(Dsw) and mechanical properties of these composites membranes were studied by means of IR analysis and tensile testing. The experimental results showed that both mechanical properties of these composites were significantly improved by using the as-synthesized filler. The filler synthesized in this research not only increased the volume and reduce the cost of HPDMS, but also reacted with the PDMS. The vulcanztion density was increasedwith the interaction between the filler and the PDMS chains. This new kind of silica microspheres is an effective reinforcement filler for PDMS composite.

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