Structural Reliability Assessment Based on the Improved Constrained Differential Evolution Algorithm

In this work, the reliability analysis is employed to take into account the uncertainties in a structure. Reliability analysis is a tool to compute the probability of failure corresponding to a given failure mode. In this study, one of the most commonly used reliability analysis method namely first order reliability method is used to calculate the probability of failure. Since finding the most probable point (MPP) or design point is a constrained optimization problem, in contrast to all the previous studies based on the penalty function method or the preference of the feasible solutions technique, in this study one of the latest versions of the differential evolution metaheuristic algorithm named improved (μ+λ)-constrained differential evolution (ICDE) based on the multi-objective constraint-handling technique is utilized. The ICDE is very easy to implement because there is no need to the time-consuming task of fine tuning of the penalty parameters. Several test problems are used to verify the accuracy and efficiency of the ICDE. The statistical comparisons revealed that the performance of ICDE is better than or comparable with the other considered methods. Also, it shows acceptable convergence rate in the process of finding the design point. According to the results and easier implementation of ICDE, it can be expected that the proposed method would become a robust alternative to the penalty function based methods for the reliability assessment problems in the future works

System Reliability Based Design Optimization of Truss Structures with Interval Variables

New products ranging from simple components to complex structures should be designed to be optimal and reliable. In this paper, for the first time, a hybrid uncertain model is applied to system reliability based design optimization (RBDO) of trusses. All uncertain variables are described by random distributions but those lack information are defined by variation intervals. For system RBDO of trusses, the first order reliability method, as well as an equivalent model and the branch and bound method, are utilized to determine the system failure probability; and Improved (μ + λ) constrained differential evolution (ICDE) is employed for the optimization process. Reliability assessment of some engineering examples is proposed to verify our results. Moreover, the effect interval variables on the optimum weight of the truss structures are investigated. The results indicate that the optimal weight depends not only on the uncertainty level but also on the equivalent standard deviation; and a falling-rising behavior is observed

On the design of a wheel assembly for a race car

Formula SAE (FSAE) is a competition where university students are challenged to design, fabricate and race small open-wheeled vehicles. This work outlines the development and analysis of a wheel assembly for a race car which carried out by the James Cook University Motorsports. A number of strategies are utilized throughout the paper including load calculations, modelling by SolidWorks and finite element analysis via Ansys for each part of the system including the upright, braking system and hub shaft

Composite shaftless roller design for conveyor system

Improving the performance of idlers is paramount to the performance of the conveyor system in various industries since belt conveyors can be many kilometers in length and consequently there are a huge number of rollers in use. The key intention of this work is the development of a light-weight composite idler roller. Critical design considerations are strength-to-weight ratio and performance. Most importantly, the design must reduce the weight of the roller as compared to standard steel rollers. The final design provides a significant reduction in weight of about 47 % over that of traditional steel rollers of a similar size

On the Design of the Manifold for a Race Car

This paper involves the design and construction of the intake manifold system of the FSAE car including the air shroud, air filter, throttle body, restrictor plenum, fuel injectors, fuel rail and runners. To ensure the quality, the proposed system is designed based on the FSAE rules. The design process of the intake manifold system will consist of the usual engineering processes including computer modelling, Finite Element Analysis and finally Computational Fluid Dynamics testing in order to determine the validity of the model and to tune the design in order to obtain the optimum performance out of the intake manifold system as a whole

On the design of the manifold for a race car

This paper involves the design and construction of the intake manifold system of the FSAE car including the air shroud, air filter, throttle body, restrictor plenum, fuel injectors, fuel rail and runners. To ensure the quality, the proposed system is designed based on the FSAE rules. The design process of the intake manifold system will consist of the usual engineering processes including computer modelling, Finite Element Analysis and finally Computational Fluid Dynamics testing in order to determine the validity of the model and to tune the design in order to obtain the optimum performance out of the intake manifold system as a whole

A compact and portable design development of a low rolling resistance test rig

Low Rolling Resistance (LRR) conveyor systems are generally preferred over traditional conveyors because of better overall efficiency lesser energy consumption required to operate. In this work, the design development and analysis path in the process of downscaling the size of an existent LRR test rig to a compact, portable and desktop-sized model is presented. Simulation has been developed using SolidWorks and finite element analysis is conducted using ANSYS to obtain the deformation, stress and strain of each part of the new design

Comparison the effectiveness of Emotion-Focused Couple and Acceptance and Commitment Therapies on Marital Forgiveness in Incompatible Couples

Background: Using effective interventions to reduce incompatibility among couples can play a role in preventing divorce in the family. The present study aimed to compare the effectiveness of emotion-focused couple therapy (EFCT) and acceptance and commitment therapy (ACT) on forgiveness in incompatible couples. Methods: The present research is a quasi-experimental study that was done on couples referred to a family therapy clinic in Torbat-e-Jam City. Here, 24 incompatible couples were selected through purposive methods and randomly replaced in three groups. The first and second groups (8 couples in each group) received emotion-focused couples and acceptance and commitment therapies, respectively, and the third group as control (8 couples) did not receive any intervention during the study period. All three groups were evaluated before and after the intervention with a standard questionnaire of Bagarozi forgiveness (2001). Data were analyzed through SPSS software version 20 and covariance analysis. Results: The findings revealed that both therapies of EFCT and ACT had a meaningful effect on forgiveness (P < 0.001, F = 41.73, and P = 0.031, F = 5.13; respectively); while the results indicated that the two groups under intervention have no significant difference in terms of effectiveness on the variable of forgiveness (P=0.63, F=0.23). Conclusion: According to the results and effectiveness of the two therapy groups, it is recommended to use a combination of approaches according to the therapeutic goals