Search results

This study aims to clarify the relationship between the coefficient of friction (COF) and temperature of aluminum-based brake discs.

Three friction blocks with different COFs are examined by a TM-I-type reduced-scale inertial braking dynamometer. On this basis, the thermo-mechanically coupled model of friction pairs is established to study the evolution of brake disc temperature under different COFs using ADINA software.

Results indicate that the calculated disc temperature field matches the experimental well. The effect of COF on the peak temperature is magnified by the braking speed. With the COF increasing, the rise rate of instantaneous peak temperature is accelerated, and the dynamic equilibrium period and cooling-down period are observed in advance. The increase in COF promotes the area ratio of the high-temperature zone and the maximum radial temperature difference. When the COF is increased from 0.245 to 0.359 and 0.434 at 140 km/h, the area ratio of high-temperature zone increases from 12% to 44% and 49% and the maximum radial temperature difference increases from 56°C to 75°C and 83°C. The sensitiveness of the axial temperature difference to the COF is related to the braking time. The maximum axial temperature difference increases with COF in the early stages of braking, while it is hardly sensitive to the COF in the later stages of braking.

The effect of COF on the aluminum-based brake disc temperature is revealed, providing a theoretical reference for the popularization of aluminum-based brake discs and the selection of matching brake pads.

This study aims to clarify the relationship of friction material type and brake disc temperature through braking experiment.

The braking performances of resin materials (RM), semimetallic materials (SM) and copper-based powder metallurgy materials (PM) friction blocks mating with forged steel brake disc were examined based on TM-I-type reduced-scale inertial braking dynamometer. The brake disc surface temperature was recorded by infrared thermal camera during braking.

Experimental results indicate that the thermal wear resistance of three friction materials differs with mental content, resulting in the deviation of pad-disc system contact state during braking, thus forming different temperature distribution on the brake disc surface. The peak temperature on the disc face of RM (190°C) is 36.6% and 45.4% lower than that of PM (300°C) and SM (348°C) at 160 km/h. The maximum radial temperature deviation of PM (35°C) is approximately three times than that of RM (12°C) and 40% higher than that of SM (25°C) at 50 km/h, whereas the maximum temperature deviation of SM (97°C) is six times than that of RM (16°C) and 31% higher than that of PM (74°C) at 160 km/h.

The effect of friction material type on the disc surface temperature distribution is revealed, which provides a meaningful reference for the design of brake friction pairs and choice of brake pad materials.

The aim of this study is to construct a model that can be used to predict the architect's overall performance in the Nigeria building delivery process and to provide adequate understanding of the criteria which constitute the model. Architect performance criteria were identified from existing literature within the domain of architect responsibilities and developed into a two‐part questionnaire survey. The survey involves clients of recently completed building projects in Nigeria. The first part of the questionnaire survey consists of 71 clients which were used to construct the model while the second part consists of another 17 clients which were used to validate the model. Based on this data, a predictive discriminant analysis model of two‐group cases (good and poor performance) was developed. The model shows that the predicted architect's overall performance is significantly correlated with the actual validated client ratings (0.783 at 99% confidence interval). The results show that if architects want to achieve good performance, they should give a high level of performance to ‘effective communication of design to contractor and other participants’; ‘effective constructability review’; ‘assistance in quality management strategies and clarity and consistency of specification with drawings’. The study would give architects a fore knowledge on how to ensure good performance in their future enterprise.

The purpose of this paper is to elicit the activities in geometric 3D computer-aided design (CAD) estimating. Construction estimators usually target the structural integrity of data underlying project designs while measuring quantities and developing estimates. However, there are different ways to this. There is considerable evidence to suggest substantial distinction between data structuring in geometric and parametric CAD (building information modelling). Each of these platforms also appeals to estimators in the various practice domains differently. Regardless, the developments in the use of geometric and parametric CAD for design and management purposes have been rapid.

The study focuses on the various perspectives within the different construction business domains. Interviews, focus group discussions and direct observation methods were used to explore data on estimating activities in 3D CAD from two public organizations, two large contracting firms, two quantity surveying consulting practices, two specialist-project companies and four software development and vending firms. These involved 17 middle-top management estimators who have had extensive experience in the industry. As the activities were elicited, participants were able to ascribe relative importance to each of the activities, and these were logically compared across the different practice domains.

Thirty-one activities were identified as the components of estimators’ procedures leading to reliable outcomes in estimating 3D CAD designs. Logical correlations were discussed through extant literature towards forming a centroid model which could be used for numerous industry applications, including software development, knowledge transfer between organizations, employees’ hands-on training, curriculum design for academic institutions and as a policy framework for professional institutions on estimating practice. Further areas of research were also highlighted.

This work is an original piece. It is neither published nor under consideration elsewhere.