Carbon steel bolts have been broadly utilized in modern building construction. Fire performance of these components has investigated the published journals aiming at deriving their reduction factors elevated temperatures. However, it should be noted that materials employed for manufacturing high-strength structural may different from country to country. Meanwhile, present research efforts mainly focused on fire carbon instead material properties. Therefore, this paper developed an...

In recent years, sites with low annual average wind speeds have begun to be considered for the development of new farms. The majority design methods a turbine operating at speed is increase blade length or hub height compared in high sites. cost rotor and tower considerable portion overall cost. This study investigates method trade-off during optimization speeds. A scaling model implemented evaluate energy. procedure optimizes blades’ aero-structural performance considering simultaneously....

In this paper, a task space-based methodology for dynamic trajectory planning digging process of hydraulic excavator is presented, with the integration soil–bucket interaction. An extended interaction model, which adds resistive moment compared to previous models, provided in research. This improved model validated by comparing measurement data taken from field experiments before integrating it into an excavator. Further, Newton–Euler method used derivation dynamics each link determine joint...

This paper presents a methodology for lightweight and high‐strength design of an excavator bucket under uncertain loading. Uncertain loads are obtained by using the Monte Carlo simulation based on existing soil‐bucket interaction model in which soil parameters variable. And well‐known 3‐sigma is used quantification loads. Excavator modelling finished ANSYS Parameter Design Language (APDL). A multiobjective optimization aiming to decrease maximum von Mises stress reduce weight established...

A methodology whereby the digging performance of hydraulic excavator can be determined is presented, with uncertainty during operation being taken into consideration. Natural variability in medium properties and differences styles are significant sources uncertainty. The most probable direction interval resistance obtained from experimental data given to quantify contribution uncertain variation direction. capability polygon, which used characterize excavator’s apply forces overcome...

This paper presents a methodology for the optimization design of fully parametric working attachment hydraulic excavator with weight reduction and maximum stress minimization as objectives. A novel 3D force output model named limiting theoretical digging capability is proposed to completely accurately calculate moment an can apply in preferred bucket space. On basis this model, joint forces acting on are calculated. Further, critical condition loads used structure be determined by using...

The direction and magnitude of the digging resistance encountered by an excavator during process are usually uncertain. To identify excavator’s capability to generate force overcome in any direction, a hexahedral actuator space is mapped polygon bucket with consideration whole machine stability constraints excavator. Then this called polygon. Based on polygon, maximum force, isotropy measure full exertion proportion measures driving working hydraulic cylinders defined quantify performance...

A new approach for shape optimization of hydrodynamic journal bearings using a profile parameterization method has been evaluated. mathematical model derived the solution lubrication equations. Fourier series function was used to represent general film geometry in bearing. The objective then determine coefficients that maximized load capacity with constraint on minimum thickness. model, based Reynolds equation, solved PDE Toolbox MATLAB. process achieved genetic algorithm (GA) also available...

Abstract The theoretical digging force is the maximum resistance that an excavator can overcome, which important measure of its capacity. To study matching capacity with actual demand and working device mechanism, a 36.5 t backhoe hydraulic used as example to analyse distributions under two different normal area conditions characteristics tool. An appropriate postures are selected, based on limit compound models, forces obtained matched measured values limiting factors affecting force....

Resistance characteristics research lays a foundation for establishing and improving excavator performance evaluation. Therefore, thorough understanding of the general laws governing excavation resistance is particularly significant. Based on experimental data from 8 sets conditions involving two types 20 t backhoe hydraulic excavator, this paper first conducted comparative analysis distribution trends concentration coefficients, moment angles, differential component rotation angular...

since structural analysis has been rely too much on simulation softwares which cause great computer occupation and is hard to re-develop for optimization, the research optimized design of working device based classic mechanic theory was proposed. After taking in analysis, cross-section simplified get maximum stress standard occasion, included VB programmed software called self-compiled software(SSAS). Reliability SSAS verified through comparing result ANSYS simulation. Then, optimization had...

Abstract The evaluation of excavator performance relies heavily on digging force, which serves as a crucial indicator. However, the accuracy assessment is hindered by absence suitable method to characterize dynamic capacity excavators. This study addresses this limitation proposing an approach establish set solution-limited inequalities for force. incorporates D’Alembert’s principle and composite digging, while considering influence inertia Furthermore, mitigate issue bucket tooth tip...

The structural parameter of excavator attachment plays an important role in the design, so it is very to select most dangerous working condition improve strength by optimizing parameters.However, previous traditional comes from specialized mechanism parameters, which may not be appropriate real digging process.Moreover, excavators same tonnage are quite different number and position inside reinforce plate.In this paper, actual concluded performance testing a certain backhoe hydraulic...

In order to improve the performance of hydrodynamic journal bearings, effect bearing profiles had been investigated using a new approach for shape optimization bearings based on profile parameterization method. The process was carried out Fourier series describe profile. load capacity increases with increasing series. However optimized result almost fully achieved at 2. this paper, three kinds shapes general film thickness equation 1, 2 and 3 were manufactured taken as experimental objects...