A Study of Stress Factors and Their Impact on Students’ Academic Performance at University Level

The main emphasis of the study is on the academic performance and the stress management in applied science among the students of Mohtarma Benazir Bhutto Shaheed Sindh University Campus Dadu. What is the level of stress on the academic success of the students? How does it affect their lifestyle and health? This is what the research study covers to counteract the general stress among the students. The purpose of the study is to inquire and bring light to measure and check the present stress among students of the university. While doing the research a quantitative method was applied for collecting and analyzing the data. The Questionnaires were distributed among different students for this purpose. Innumerable factors of stress were found in the results and the factors were grouped in four categories which are; -Environmental Factors, Academic Factors, and Personal Factors. In environmental factors, the stress was about the happening the fate in the future. The students were found worried about future that what would happen about their fate? How it will happen? What is about to happen? When they came into contact with the new people it raised their stress. Also the class workload was the main reason for the stress among the students regarding academic factors. When the students were experiencing the workload of the class the group of the students came under stress. The last factor was a personal factor which was mainly due to the financial problem among the students. The stress of all categories can be managed through stress management courses and doing different extracurricular activities which will help to divert the attention of the students on different occasions. This study has drawn significant conclusions and Suggests further measures for practitioners which could help other to manage stress. The limitations are also mentioned so that those who are conducting research for the similar cases can extract better results and ways of curbing stress. A survey questionnaire was designed to collect the response from students, the five-point Likert scale was used from strongly agree to strongly disagree. SPSS-21 version was used to interpret the results through different quantitative techniques like descriptive, regression, and correlation. ____________

Modeling of Damage Growth in Frp Composites With Stress Raisers Such As Holes and Notches

Fibre reinforced polymer composite panels are preferred in high performance structural panels because they are strong, stiff and light. Stress raisers such as holes or notches (for accessibility, mechanical joining, and routing of cables etc.) may be present in any engineering structure and composite structures are no exception. Theoretically, a stress raiser is simply a localization of high stress-strain concentrations quantified by the Stress Concentration Factor (SCF). It is well established in literature and engineering practice that stress-strain concentrations due to holes or notches, unless accompanied by local plastic strain hardening, reduce the apparent strength of the panels. Since SCF is a function of elastic properties of the material, so in isotropic materials, the SCF is defined with elastic SCF (entails elastic properties within the elastic range of material) and plastic SCF (entails elastic properties in the plastic range of material). However, literature is scarce of such definition for the case of anisotropic/orthotropic materials, where the SCF is also a function of its elastic properties. Contrary to isotropic homogenous materials, composite panels offer a very complex structure, where fibres are generally regarded as brittle which deform elastically to final failure exhibiting either slight or no linear deformation. Whereas matrices generally experience plastic deformation hence the failure strain in matrics is far higher than the fibres. Additionally, once a composite panel containing a hole is subjected to tensile loading, tangential stress at the periphery of the hole in a perpendicular direction to the load axis attains a magnitude three times the far field stress under plane stress conditions. However, in a composite panel, the location and magnitude of the maximum stress are at the periphery of the hole changes with the fibre orientation and stacking sequence, therefore designers opt for large safety margins. This study has been performed to investigate the pre-damaged SCF and progressive-damaged SCF for anisotropic/orthotropic material analogous to elastic and plastic deformations in isotropic material respectively. The study presents a novel technique of calculating progressive-damaged SCF which evaluates the changing SCF in response to the progressive damage development within the composite panel. Finite Element (FE) representations simulate delamination damage using cohesive elements and in-plane damage using continuum damage mechanics. In the first part of the study, test coupons have been formulated under static conditions to consider important influencing factors on the SCF for the case of the composite panel containing a central circular hole subjected to tensile loading and compared with the already published literature. Later, several xii FE coupons have been formulated to precisely investigate the pre-damaged SCF and progressivedamaged SCF for the composite panel. During the study, the investigations of pre-damaged SCF and progressive-damaged SCF have also been performed using analytical and experimental approaches where applicable. The FE results are found in good agreement with the analytical and experimental results. The study provides a novel systematic FE approach for the estimation of progressive-damaged SCF for a composite panel, which has not been reported in the literature before. Certainly, the study proposes a paradigm shift in design philosophy which at present is limited to no-damage philosophy especially in aerospace, where the weight savings due to less generous safety factors are significant.