This study proposes using KH-550 as a multifunctional admixture for improving the performance of alkali-activated slag (AAS). The hydrolysis products were characterized, and influence on fresh properties, hydration kinetics, pore structure, capillary water absorption, products, compressive strength micro-mechanical properties AAS investigated. results showed that addition improved AAS. By adding 2.5 % KH-550, initial final setting time prolonged by 105.1 60.3 %, respectively, fluidity was...

The theoretically optimal performance of seat belt systems for occupants in automobile frontal crashes is investigated based on a two-mass injury model the thorax. measured by thoracic criteria which include maximum chest acceleration, compression and viscous response. relationship between best possible (limiting performance) system distance occupant interior components vehicle displayed form trade-off curves, can be used evaluation performance. characteristics force kinematics are...

Plasma carburizing of AISI 316L austenitic stainless steel was carried out at low temperature to improve the surface hardness without degradation its corrosion resistance. And post-treatment, namely electrochemical brightening process clear away a layer thin black film on plasma carburized samples and quality hardened steel. The appearance, roughness, microstructures, microhardness resistance before after were analyzed compared. Experimental results showed that high-quality layers can be...

Abstract The theoretically optimal performance of a helicopter seat cushion for the reduction spinal injuries during vertical crashes is investigated using limiting analysis. dynamic response index and maximum compression load are used as system indices to be minimized. Three types cushions (passive, active, pre-acting) studied. A trade-off curve control force each type obtained. Computational results indicate that prevention injuries, pre-acting superior active non-pre-acting cushion, which...

This is a study of the theoretical optimal (limiting) performance helmets for prevention head injury. A rigid injury model and two‐mass translational are employed. Several criteria utilized, including acceleration, criterion (HIC), energy imparted to brain which related injury, power developed in skull that associated with fracture. helmeted hitting surface hit by moving object such as ball considered. The characteristics impact responses investigated computationally. An experiment conducted...

Micro-nanostructure coatings have been attempted to prepare by Electro-spark deposition (ESD) on cast iron substrate. The microstructures and properties of the coating were investigated X-ray diffractometer (XRD), scanning electron microscopy (SEM) microhardness tester. results show that micro-nanosized particles fine equiaxed structures prevail in coating. primary phases contain Fe3W3C, Co3W3C, Fe7W6 W2C. Its average reaches 1290.1 HV. abrasive test demonstrated had an excellent sliding...

To improve the mechanical product hardness, wear resistance and corrosion resistance, Fe-SiC composite plating process properties have been studied. By using self-made asymmetric AC - DC power supply adding SiC in ferrous chloride bath, high performance coatings are prepared by electrodeposition method. The effect of Phase, composition particle content on surface morphology, structure, parameters optimized. results show that micro-cracks will reduced increased particles under condition...

Abstract The performance of safety devices for injury control is studied in this paper. problem to be addressed treated as the optimal and optimization a biomechanical system consisting occupants. measured by criteria. limiting analysis utilized find best possible system. Parametric introduced design device. Various techniques computational modeling systems are discussed. use nonlinear rigid multi-body dynamics software parametric addressed. Best worst disturbance analyses sensitivity also...

Abstract The distribution of mineral grains within underground rocks and materials is crucial for understanding geological processes the stability engineering structures. However, numerical simulation methods that consider 3D particles are still immature. This study presents a phase-field fracture model based on Voronoi polygons, making some beneficial attempts in this regard. method does not rely mesh reconstruction or crack path tracking can simulate complex propagation behavior....

Abstract Determining the position of crack tip is crucial for rock fracture characteristic analysis. This study aims to establish a quantitative standard determining positions in crystalline rocks based on digital image correlation (DIC). Semi-circular bending (SCB) tests were conducted four types under three-point bending. Optical microscopy and DIC used investigate characteristics horizontal displacement fields around tips. A significant disparity gradient was observed across tips, with...

In this paper, we consider the adaptive linear quadratic Gaussian control problem, where both transformation matrix of state $A$ and gain $B$ are unknown. The proposed optimal only assumes that $(A, B)$ is stabilizable Q^{1/2})$ detectable, $Q$ weighting in cost function. This condition significantly weakens classic assumptions used literature. To tackle a weighted least squares algorithm modified by using random regularization method, which can ensure uniform stabilizability detectability...

The theoretically optimal performance of seat belt systems for occupants in automobile frontal crashes is investigated based on a two-mass injury model the thorax. measured by thoracic criteria which include maximum chest acceleration, compression and viscous response. relationship between best possible (limiting performance) system distance occupant interior components vehicle displayed form trade-off curves, can be used evaluation performance. characteristics force kinematics are...

By using self-made asymmetric AC - DC power supply and adding SiC in ferrous chloride bath, the high performance Fe-SiC iron-based composite coatings were prepared by electrodeposition method. The effect of Phase, composition particle content on surface morphology, structure, hardness, wear resistance corrosion studied. process parameters plating optimized. results showed that micro-cracks would reduced will increased particles under condition optimum process.