Damage is an inevitable occurrence in metallic structures and when unchecked could result in a catastrophic breakdown of structural assets. Non-destructive evaluation (NDE) is adopted in industries for assessment and health inspection of structural assets. Prominent among the NDE techniques is guided wave ultrasonic testing (GWUT). This method is cost-effective and possesses an enormous capability for long-range inspection of corroded structures, detection of sundries of crack and other metallic damage structures at low frequency and energy attenuation. However, the parametric features of the GWUT are affected by structural and environmental operating conditions and result in masking damage signal. Most studies focused on identifying individual damage under varying conditions while combined damage phenomena can coexist in structure and hasten its deterioration. Hence, it is an impending task to study the effect of combined damage on a structure under varying conditions and correlate it with GWUT parametric features. In this respect, this work reviewed the literature on UGWs, damage inspection, severity, temperature influence on the guided wave and parametric characteristics of the inspecting wave. The review is limited to the piezoelectric transduction unit. It was keenly observed that no significant work had been done to correlate the parametric feature of GWUT with combined damage effect under varying conditions. It is therefore proposed to investigate this impending task.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

No abstract

The harsh weather condition experienced in Nigeria, especially during the dry season, is of concern for the comfort of human inhabitants. During the day, vehicles parked under direct and scorching sunlight with the window glasses closed tend to build up high temperature inside the cabin. The upsurge in temperature inside the car poses serious discomfort and potential ill health to the vehicle occupants when they return to use it. This study focused on the degree of temperature rise as well as on the rate of rise at specific positions inside the cabin of a saloon vehicle parked under intense sun. The vehicle was parked in North-South direction under direct sunlight at the University of Nigeria Nsukka campus. Two cases were adopted in the study. Case A involved winding up the window glasses for a long period of 5 hours while in Case B, the effect of having the two front glass windows lowered with a gap of 0.04m and monitored for 5 hours was evaluated. The vehicle cabin temperature was measured at different locations of the cabin using LM35 DZ temperature sensor. The maximum cabin air temperatures were recorded at the dashboard, rear compartment, driver head rest and center of back seat which gave temperatures of 72.4 0 C, 72.4 0 C, 62.6 0 C, 60.2 0 C respectively for Case A. For Case B, the maximum temperatures were 56.2 0 C, 60.6 0 C, 52.8 0 C, 48.4 0 C, respectively. It was deduced that air temperature in the cabin can increase to health threatening temperature in 8-10 minutes after parking under intense sunlight exposure. T-tail test analysis showed that there is statistical significant difference between the two considered Cases. It was equally deduced from the study that it is not safe to leave a child, pet or items that cannot withstand higher temperature in a parked car as such could lead to heat stroke, death and damage of items.