scholarly journals Mechanical Properties of the Connectors of Steel Frame Embedded and Hung with the Intercalated Multi-Ribbed Composite Wall

2021 ◽  
Author(s):  
Chao Gong ◽  
Mingming Jia ◽  
Xin Liu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Deformation Mode ◽  
Steel Frame ◽  
Load Bearing ◽  
Shear Connectors ◽  
Low Weight ◽  
Composite Wall ◽  
Insulation Performance ◽  
Related Design

The multi-ribbed composite wall (MRCW) structure has the advantage of energy-saving, low weight, and adjustable stiffness. The partition, enclosure, and load-bearing capacity can be realized simultaneously. When the steel frame embedded and hung with the intercalated multi-ribbed composite wall (MRCW), the steel frame columns are avoided to expose in the air, so the durability and heat insulation performance of the structure can be improved. The steel frame is connected with the intercalated multi-ribbed composite wall (MRCW) by wet connection, and the mechanical property and the deformation mode of the multi-ribbed composite wall (MRCW) and steel frame are researched. The mechanical property of stud shear connectors is qualitatively and quantitatively analyzed, which is beneficial to improve the related design methods of structures.

A general stiffness model for programmable matter and modular robotic structures

Robotica ◽  
2011 ◽  
Vol 29 (1) ◽  
pp. 103-121 ◽  
Author(s):  
Paul J. White ◽  
Shai Revzen ◽  
Chris E. Thorne ◽  
Mark Yim
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Nonlinear Modeling ◽  
Fast Method ◽  
Programmable Matter ◽  
Load Bearing ◽  
Reconfigurable Robots ◽  
Stiffness Matrices ◽  
Internal Arrangement ◽  
Modular Structures

SUMMARYThe fields of modular reconfigurable robotics and programmable matter study how to compose functionally useful systems from configurations of modules. In addition to the external shape of a module configuration, the internal arrangement of modules and bonds between them can greatly impact functionally relevant mechanical properties such as load bearing ability. A fast method to evaluate the mechanical property aids the search for an arrangement of modules achieving a desired mechanical property as the space of possible configurations grows combinatorially. We present a fast approximate method where the bonds between modules are represented with stiffness matrices that are general enough to represent a wide variety of systems and follows the natural modular decomposition of the system. The method includes nonlinear modeling such as anisotropic bonds and properties that vary as components flex. We show that the arrangement of two types of bonds within a programmable matter systems enables programming the apparent elasticity of the structure. We also present a method to experimentally determine the stiffness matrix for chain style reconfigurable robots. The efficacy of applying the method is demonstrated on the CKBot modular robot and two programmable matter systems: the Rubik's snake folding chain toy and a right angle tetrahedron chain called RATChET7mm. By allowing the design space to be rapidly explored we open the door to optimizing modular structures for desired mechanical properties such as enhanced load bearing and robustness.

Mechanical Property Studies on Flax Fiber Reinforced Basalt Powder Filled Polyester Composite

2020 ◽  
Vol 13 ◽  
Author(s):  
V. Arumugaprabu ◽  
K.Arun Prasath ◽  
S. Mangaleswaran ◽  
M. Manikanda Raja ◽  
R. Jegan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Natural Fiber ◽  
Tensile Load ◽  
Flax Fiber ◽  
Flexural Properties ◽  
Weight Percentage ◽  
Tensile Impact ◽  
Polyester Composite ◽  
Additional Support

: The objective of this research is to evaluate the tensile, impact and flexural properties of flax fiber and basalt powder filled polyester composite. Flax fiber is one of the predominant reinforcement natural fiber which possess good mechanical properties and addition of basalt powder as a filler provides additional support to the composite. The Composites are prepared using flax fiber arranged in 10 layers with varying weight percentage of the basalt powder as 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.% and 30 wt.% respectively. From the results it is inferred that the composite combination 10 Layers of flax / 5 wt.%, basalt Powder absorbs more tensile load of 145 MPa. Also, for the same combination maximum flexural strength is about 60 MPa. Interestingly in the case of impact strength more energy was absorbed by 10 layers of flax and 30 wt.% of basalt powder. In addition, the failure mechanism of the composites also discussed briefly using SEM studies.

No more rattling: biomechanical evaluation of a hexapod ring fixator free of play

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Markus Greinwald ◽  
Emily K. Bliven ◽  
Alex Trompeter ◽  
Peter Augat
Keyword(s):  
Mechanical Performance ◽  
Steel Frame ◽  
Ball Joint ◽  
Universal Joint ◽  
Ring Fixator ◽  
Low Weight ◽  
Biomechanical Evaluation ◽  
Axial Fracture ◽  
Ball Joints ◽  
Universal Joints

Abstract Hexapod-ring-fixators have a characteristic rattling sound during load changes due to play in the hexapod struts. This play is perceived as unpleasant by patients and can lead to frame instability. Using slotted-ball-instead of universal-joints for the ring-strut connection could potentially resolve this problem. The purpose of the study was to clarify if the use of slotted-ball-joints reduces play and also fracture gap movement. A hexapod-fixator with slotted-ball-joints and aluminum struts (Ball-Al) was compared to universal-joint-fixators with either aluminum (Uni Al) or steel struts (Uni Steel). Six fixator frames each were loaded in tension, compression, torsion, bending and shear and mechanical performance was analyzed in terms of movement, stiffness and play. The slotted-ball-joint fixator was the only system without measurable axial play (<0.01 mm) compared to Uni-Al (1.2 ± 0.1) mm and Uni-Steel (0.6 ± 0.2) mm (p≤0.001). In both shear directions the Uni-Al had the largest play (p≤0.014). The resulting axial fracture gap movements were similar for the two aluminum frames and up to 25% smaller for the steel frame, mainly due to the highest stiffness found for the Uni-Steel in all loading scenarios (p≤0.036). However, the Uni-Steel construct was also up to 29% (450 g) heavier and had fewer usable mounting holes. In conclusion, the slotted-ball-joints of the Ball-Al fixator reduced play and minimized shear movement in the fracture while maintaining low weight of the construct. The heavier and stiffer Uni-Steel fixator compensates for existing play with a higher overall stiffness.

scholarly journals Regulating Effect of Cement Accelerator on High Content Solid-Wastes Autoclaved Aerated Concrete (HCS-AAC) Slurry Performance and Subsequent Influence

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 799
Author(s):  
Dingkun Xie ◽  
Lixiong Cai ◽  
Jie Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Solid Wastes ◽  
Hydration Products ◽  
Promoting Effect ◽  
Adverse Side Effects ◽  
Foaming Process ◽  
Carbide Slag ◽  
Negative Effect ◽  
Aerated Concrete

Adverse side-effects occurred in slurry foaming and thickening process when carbide slag was substituted for quicklime in HCS-AAC. Cement accelerators were introduced to modify the slurry foaming and coagulating process during pre-curing. Meanwhile, the affiliated effects on the physical-mechanical properties and hydration products were discussed to evaluate the applicability and influence of the cement accelerator. The hydration products were characterized by mineralogical (XRD) and thermal analysis (DSC-TG). The results indicated that substituting carbide slag for quicklime retarded slurry foaming and curing progress; meanwhile, the induced mechanical property declination had a negative effect on the generation of C–S–H (I) and tobermorite. Na2SO4 and Na2O·2.0SiO2 can effectively accelerate the slurry foaming rate, but the promoting effect on slurry thickening was inconspicuous. The compressive strength of HCS-AAC obviously declined with increasing cement coagulant content, which was mainly ascribed to the decrease in bulk density caused by the accelerating effect on the slurry foaming process. Dosing Na2SO4 under 0.4% has little effect on the generation of strength contributing to hydration products while the addition of Na2O·2.0SiO2 can accelerate the generation and crystallization of C–S–H, which contributed to the high activity gelatinous SiO2 generated from the reaction between Na2O·2.0SiO2 and Ca(OH)2.

Effects of Nano-Al2O3 on the Mechanical Property and Microstructure of Nano-Micro Composite Self-Lubricating Ceramic Tool Material

2013 ◽  
Vol 770 ◽  
pp. 308-311 ◽  
Author(s):  
Ming Dong Yi ◽  
Chong Hai Xu ◽  
Zhao Qiang Chen ◽  
Guang Yong Wu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Tool Material ◽  
Ceramic Tool ◽  
Ceramic Tool Material ◽  
Composite Self ◽  
Microstructure And Mechanical Property ◽  
Grain Refinement Strengthening

A new nanomicro composite self-lubricating ceramic tool material was prepared with vacuum hot pressing technique. The effect of nanoAl2O3 powders on the microstructure and mechanical properties of nanomicro composite self-lubricating ceramic tool material was investigated. With the increase of nanoAl2O3 content, the hardness and fracture toughness first up then down. When the nanoAl2O3 content is 4 vol.%, the flexural strength, hardness and fracture toughness reaches 562 MPa, 8.46 MPa·m1/2 and 18.95 GPa, respectively. The microstructure and mechanical property of nanomicro composite self-lubricating ceramic tool material can be improved by the grain refinement strengthening of nanoAl2O3.

Mechanical Properties of SiO2 vs. SiO2-TiO2 Bulk Glasses and Fibers

1991 ◽  
Vol 244 ◽  
Author(s):  
Suresh T. Gulati
Keyword(s):  
Mechanical Properties ◽  
Optical Fibers ◽  
Mechanical Performance ◽  
Fatigue Behavior ◽  
Deformation Mode ◽  
Strength Distribution ◽  
Fused Silica ◽  
Space Applications ◽  
Silica Glasses ◽  
Silica And Titania

ABSTRACTThe mechanical properties of silica and titania-doped silica glasses, in bulk and fiber forms, are presented. These include the elastic properties (E and ν), strength distribution (in tension and bending), fatigue behavior (dynamic and static loading) and fracture toughness. Following a brief review of above properties for fused silica and ULE™ glasses (Coming Codes 7940 and 7971), used primarily for space applications, the mechanical properties data for silica and titania-doped silica-clad optical fibers are presented. The enhancement of mechanical performance of titania-doped silica clad fiber is also discussed.The effect of titania doping on fundamental properties like stress-free activation energy, crack tip pH, and deformation mode of Si-O-Si bond is discussed. In addition, the crack velocity data obtained from DCDC specimens of homogeneous silica and titania-doped silica glasses are compared in an attempt to understand the role titania plays in improving the fatigue resistance of optical fibers.

Effect of Quaternary Ammonium-Modified Montmorillonites on Mechanical Properties of Polypropylene

1998 ◽  
Vol 520 ◽  
Author(s):  
Y. H. Zhang ◽  
K. C. Gong
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
Impact Strength ◽  
Quaternary Ammonium ◽  
Small Addition ◽  
Pp Composites ◽  
Addition Amount

ABSTRACTHybrids of quaternary ammonium-modified montmorillonites and polypropylene were prepared by melting intercalation. Results of mechanical property measurements show that, tensile strength, modulus and impact strength of PP composites are greatly enhanced simultaneously by a small addition amount of modified montmorillonites.

Non-Invasive Analysis of the Micro-Structural and Biomechanical Properties of Trabecular Bone in Human Femoral Head

2006 ◽  
Vol 321-323 ◽  
pp. 1070-1073
Author(s):  
Ye Yeon Won ◽  
Myong Hyun Baek ◽  
Wen Quan Cui ◽  
Kwang Kyun Kim
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Femoral Head ◽  
Trabecular Bone ◽  
Volume Fraction ◽  
Reaction Force ◽  
Bone Volume ◽  
Fe Model ◽  
Micro Ct ◽  
Trabecular Thickness

This study investigates micro-structural and mechanical properties of trabecular bone in human femoral head with and without osteoporosis using a micro-CT and a finite element model. 15 cored trabecular bone specimens with 20 of diameter were obtained from femoral heads with osteoporosis resected for total hip arthroplasty, and 5 specimens were removed from femoral head of cadavers, which has no history of musculoskeletal diseases. A high-resolution micro-CT system was used to scan each specimen to obtain histomorphometry indexes. Based on the micro-images, a FE-model was created to determine mechanical property indexes. While the non-osteoporosis group had increases the trabecular thickness, the bone volume, the bone volume fraction, the degree of anisotropy and the trabecular number compared with those of osteoporotic group, the non-osteoporotic group showed decreases in trabecular separation and structure model index. Regarding the mechanical property indexes, the reaction force and the Young's modulus were lower in the osteoporotic group than in non-osteoporotic group. Our data shows salient deteriorations in trabecular micro-structural and mechanical properties in human femoral head with osteoporosis.

Inoculation and Fading of Sr-Modified A356.2 Aluminum Alloy in Squeeze Casting

2016 ◽  
Vol 850 ◽  
pp. 671-678
Author(s):  
Jian Wei Niu ◽  
Lie Jun Li ◽  
Hai Jun Liu ◽  
Ji Xiang Gao ◽  
Chuan Dong Ren
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Aluminum Alloy ◽  
Hydrogen Absorption ◽  
Deleterious Effect ◽  
Squeeze Casting ◽  
Eutectic Silicon ◽  
Direct Reading ◽  
Air Bag ◽  
Fading Rate

The inoculation and fading behavior of Sr-modified aluminum alloy A356. 2 were studied for air bag bracket produced by squeeze casting. The effects of Sr, P, B contents and casting temperature on the microstructure and eutectic silicon morphology in different periods of inoculation were investigated by SEM and direct-reading Spectrometer. The influence of inoculation fading rate and addition of Sr on the casting mechanical properties and hydrogen absorption was studied. The experimental results showed that the inoculation process was completed in 1 h, and the eutectic silicon morphology can be maintained in almost subsequent 40 h after the addition of Sr. The fading rate decreased appreciably with the increase of casing temperature, P and B contents. The deleterious effect of the inoculation fading of Sr on the casting mechanical property can be compensated by the squeeze casting.

scholarly journals Review on the Influence of Temperature upon Hydrogen Effects in Structural Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 423
Author(s):  
Thorsten Michler ◽  
Frank Schweizer ◽  
Ken Wackermann
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Temperature Effect ◽  
Statistical Approach ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Effect Of Temperature ◽  
Engineering Applications ◽  
Selection For ◽  
Typical Temperature

It is well-documented experimentally that the influence of hydrogen on the mechanical properties of structural alloys like austenitic stainless steels, nickel superalloys, and carbon steels strongly depends on temperature. A typical curve plotting any hydrogen-affected mechanical property as a function of temperature gives a temperature THE,max, where the degradation of this mechanical property reaches a maximum. Above and below this temperature, the degradation is less. Unfortunately, the underlying physico-mechanical mechanisms are not currently understood to the level of detail required to explain such temperature effects. Though this temperature effect is important to understand in the context of engineering applications, studies to explain or even predict the effect of temperature upon the mechanical properties of structural alloys could not be identified. The available experimental data are scattered significantly, and clear trends as a function of chemistry or microstructure are difficult to see. Reported values for THE,max are in the range of about 200–340 K, which covers the typical temperature range for the design of structural components of about 230–310 K (from −40 to +40 °C). That is, the value of THE,max itself, as well as the slope of the gradient, might affect the materials selection for a dedicated application. Given the current lack of scientific understanding, a statistical approach appears to be a suitable way to account for the temperature effect in engineering applications. This study reviews the effect of temperature upon hydrogen effects in structural alloys and proposes recommendations for test temperatures for gaseous hydrogen applications.

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