Mathematical Model for Durability of Cladding

A building materials durability model (BMDM), developed in earlier work, is a framework that encompasses environmental stimuli, material damage relationships, performance criteria, and repair decision making to produce predictions of long-term performance of building materials. The framework of the model is able to accommodate a wide variety of building materials used in different applications. The current study applied the model to two cladding materials for buildings; aluminum and paint. Environmental stimuli included temperature, moisture, and impact of corrosive chemicals. The material damage models use environment as an input, and predict degradation of the cladding material. The rates of degradation in the mathematical models are tuned to fit existing data available in the literature. Quality of the cladding is calculated during the simulation, and repairs are triggered when quality falls below a predetermined threshold. Initial quality of the material and the repairs contribute to the overall cost. The results show that this general modeling tool gives the engineer a vehicle for assessing different materials, different environments, and the consequences of different repair strategies in making durability design decisions.